For more than five years, large and expensive advertisements promoting the political views of South Africa's apartheid government have been appearing in the Washington Post and other leading newspapers in Western countries.

They are attributed to a "Club of Ten" which, the ads say, is "a group of international businessmen formed to draw attention to world double standards." The London agents of the "Club" refuse to identify their paymasters. One insists that they are public spirited businessmen from South Africa and elsewhere.

There are, however, many indications that the businessmen are a fictitious front, that the Club is a creature of South Africa's now-dissolved Department of Information, the country's propaganda ministry. Among the signs, direct and indirect, are these:

Connie Mulder, the minister of information, has acknowledged that his department used secret funds for secret organizations. He declines to comment on whether the Club of Ten is one of these. In contrast, he emphatically denies any sponsorship of two pro-government publications with which he has been linked the magazine "To the Point" and the daily newspaper "The Citizen."

Donald Boddie, the Club's "London administrator," says the copy from South Africa. He says however, that he does not know the source of either. "The less I know the better," he said in an interview. "Knowledge is dangerous."

Gerald Sparrow, Boddie's predecessor, tells different stories at different times, but has been consistent in saying that the Club was invented by Mulder's ministry and is controlled by it.

The London ad agency that buys the space in The Post and other papers says, "We don't make prime presentation of the copy. We make format suggestions and that's it."

In its annual report last year, Mulder's ministry complained that the "government's credibility was described as very low." It urged "imaginative large-scale moves" and cited "Financially aimed advertisements" in West Germany as an example.

While apparently it is not illegal for the South African government to place political ads, even disguised as the product of unidentified businessmen, British intelligence has looked into the Club and discovered that the funds from South Africa are transmitted through a "double cutout," or two dummy recipients. The investigators concluded that British interests were not harmed by the Club's activities.

The ads do raise a question of journalistic ethics that may cause some soul-searching in advertising departments, however. Many papers believe that a free press should be open to any view point with the price of space. But the question raised by the Club of Ten is whether a newspaper should open its columns to special pleading of disguised or undisclosed origin.

The Club's future is questionable because a scandal has erupted over misuse of Mulder's secret funds.The South African parliament never authorized the money, and has been told that some of it went for lavish trips by ministry officials and their wives, overpayments to favored book publishers, and the use of a private travel agency instead of the government service. Expense account vouchers for ministry officials have been destroyed.

The scandal caused Prime Minister John Vorster to dissolve the Department of Information and forced the "retirement" of Mulder's deputy, ministry secretary Eschel Rhoodie, and Rhoodie's brother Deneys.

A third brother, Nic, a professor of sociology, was described by the press spokesman for the South African Embassy here as having "nothing to do with the department." However, Prof. Nic Rhoodie was forced to return about $480 of the Minsitry of Information last year when it was disclosed that he has been overpaid for a contribution to its yearbook.

Mulder will not comment for the record on whether the Rhoodies were fired for [WORD ILLEGIBLE] propaganda funds like those the government may be spending off the [WORD ILLEGIBLE] official has indicated, however, that the government is satisfied with the ministry's propaganda effort and that the Rhoodies' sins were "administrative."

Boddie, a former editor of the Evening News here and London conduit for Club of Ten copy and money, believes the ad campaign will continue, bigger than ever.

He said that he received $467,000 for the 1976 campaign and $484,000 for last year's effort, and that "a considerable further increase" is budgeted for this year.

Will the scandal end or trim the Club's activities?

"I have received no indication there is any change . . .," he replied. "The operation is in a state of big expansion." As an example, he said, Time magazine has been added to teh list of outlets.

"We tend to drop off in the summer and come back strong in September," Boddie said.

Whoever prepares the copy - the Rand Daily Mail in Johannesburg has identified the author as Les de Villiers, a former ministry official - does a professional job.

De Villiers now works for Sidney Baron, a New York public relations firm that serves South Africa and other governments with a right-wing philosphy.

The Club of Ten ads, with bold headlines and pictures accompanying the text, are eminently readable. A typical theme is that President Carter, British Foreign Minister David Owen and Andrew Young, U.S. ambassador to the United Nations, practice a "double standard" by deploring racism in South Africa but not in nations ruled by black Africans.

Until the black "homeland" of Transkei embarrassed Pretoria, some ads argued that this reserve created by the government was a genuinely independent nation, worthy of the world's recognition. At least one ad included a map that carefully hid the fact that the "homeland" consists of three parcels of non-contiguous territory.

The most voluble source of information about the Club is Gerald Sparrow, who preceded Boddie as the recipient of letters at the Club's London mail drop. The problem is that sparrow's stories vary with his listener. He declined to be interviewed by The Washington Post unless be received a fee.

In December 1976, Sparrow - then no longer the Club's London Man - told the BBC that Mulder "proposed that I should run their political advertising campaign, which was very important to him."

He continued: "I think (the South African government) blessed the matter and originally promoted it but then handed it over to the five millionaires, who were deeply committed and interested in the matter."

More recently, Mulder and the millionaires have faded from Sparrow's accounts.

In copyrighted articles appearing under his name in the Rand Daily Mail, Sparrow identified Eschel Rhoodie as the Club's "mastermind" and inventor of its name. Sparrow attributed the title to Rhoodie's concern that "some of the most prestigious papers might have declined the advertisements if they had come directly fromt he (information) department."

"I paid for the advertisements with funds provided by the Department of information either directly or through intermediaries," Sparrow wrote. He told a Rand Daily Mail interviewer, "I do not think the businessmen were in any way financially involved."

Sparrow, a 71-year-old British barrister who was president of the Cambridge University Union for one term in 1925, lived for some years in Bangkok.

He served the Club of Ten for nearly three years before being replaced by Boddie. Sparrow says he left because he and his Thai wife discovered the evils of apartheid.

Sparrow has never disclosed what he was paid but has said he received a commission on the ads.

Boddie, the Club's current conduit, gets angry when Sparrow's name is mentioned. "He is . . . on them like that," Boddie said. "I don't have a good deal of time for a man like that."

The role - if any - of the "international businessmen" cited in the Club's ads is murky. In the days when he was on the payroll, Sparrow said the Club was variously backed by 32, six or five wealthy men. At a press conference Sparrow staged in 1974, he presented one man, Charalampos Nichas, a rich South African Greek who handed over a check for 50,000 rand or $48,000 at today's rates. In response to a British Foreign Office request, Sparrow turned in the names of four or five businessmen-backers. The Foreign office refuses to make them public.

Boddie says Nichas recruited him to replace Sparrow in December 1975. Boddie was told the Club includes one American, one West Germen and several South Africans - "very private people who didn't want to identify themselves publicly."

Over the years, British and South African newspapers have speculated frequently about who tey are. The Washington Post was able to reach some who have been named.

Jan Pickard, a wealthy South African businessman, said he was a member of the Club but refused to answer any other questions.

Louis Luyt, South Africa's "fertilizer king" and former owner of the pro-government newspaper The Citizen, said he knows nothing of the Club.

Axel Springer, West German newspaper tycoon, has been identified as a prospective publishing partner of Luyt but Springer's office said he had no connection with the Club.

John McGoff, a Michigan publisher, also said he knows nothing of the Club.

Certainly several of these businessmen have close ties to Information Ministry figures. One link is the Reenberg Co. in South Africa, owner of a game farm in the eastern Transvaal. Reenberg's owners include, McGoff, De Villiers. Mulder and Eschel, Deneys and Nic Rhoodie.

Ads for the club list only one name, Boddie, and give as an address "Kent House, [WORD ILLEGIBLE] Regent Street, London." Neither Boddie nor the Club can be found there, however. It is a two-room suite on the fourth floor of a modest office building, and is occupied by a woman telephone operator and two men who declined to give their names to a reporter. One of the men said that their "Suite 66" does not receive much mail for Club, that they serve several other clients as a letter drop, and that they also serve as "management consultants."

The floor directory says Suite 66 is occupied by "Bannerman and Coleman." The man who spoke briefly with the Washington Post was introduced as "Mr. Coleman."