Former South African information official Eschel Rhoodie has given BBC television a document he says will prove that top South African officials approved an illegal multimillion-dollar government public relations campaign.

British television officials said the documents, bearing the signatures of former prime minister John Vorster, and Finance Minister Owen Horwood, will be shows on television here Wednesday during a lengthy BBC interview with Rhoodie.

The BBC interview, taped during a pearance of the document should lead to the resignation of South African Prime Minister Pieter W. Botha, who has vowed to dissolve his government and call new national elections if anyone in his Cabinet was involved in the influence-buying scandal.

The BBC in review, taped during a six-hour session last weekend, will be the first televised account Rhoodie has given of his role in the scandal since he went into hiding in Europe, and the document is the first he has produced to back up his charges that South African Cabinet members were involved.

BBC correspondent David Dimbleby, who interviewed Rhoodie, would not disclose details of the document before Wednesday's broadcast, except to say it appeared to be genuine. The document is in Afrikaans, and has been translated into English for viewers in Britain.

Dimbleby did provide reporters today with a tape recording of a portion of the interview in which Rhoodie said he also had "safely locked away somewhere in a bank vault somewhere in Europe" another "massive document" detailing all the "secret projects over the past five years, including current projects," in which South African money was spent to buy foreign support.

He said this document contained "a summary of the projects, including who received what and the names of people in the field," complete with "code numbers, code names, file numbers, amounts of money sent" and the names of recipients.

South African newspapers have quoted Rhoodie and associates of his as saying that money was given to politicians and others in positions of influence in the United States, Europe and Africa in a "propaganda war in which no rules or regulations would count."

In the BBC interview, Rhoodie acknowledged that he ran the influence-buying campaign, but with the complete approval of South Africa's highest officials.

In addition to the documentary proof, Rhoodie said, "being the man in charge, my memory serves as a record, and I have dictated everything I know onto tapes. I also have other tapes that were not dictated."

Rhoodie had offered to reveal more documents and some contents of the tapes if BBC paid him $200,000, Dimbleby and Harrison said, but they refused. "He was told that was ridiculous," said Dimbleby, who emphasized that BBC paid Rhoodie nothing.

A South African government commission investigating the influence-buying scandal reported in December that Rhoodie and his boss, former information minister Cornelius Mulder, and former South African security chief Gen. Hendrik van den Bergh were primarily responsible for the influence-buying scheme. Mulder was forced to resign from the Cabinet and Parliament. Van den Bergh already had retired from government.

The government commission said about $74 million was spent between 1973 and 1978, about half of which financed The Citizen, a progovernment newspaper that Rhoodie set up. The commission said it could not reveal how the other $37 million was spent because it would endanger South Africa's national security and its relations with other countries.

BBC producer Harrison said that Rhoodie agreed to the interview, his first for television since going into hiding, because "he's obviously trying to clear his name." South Africa has issued an arrest warrant for Rhoodie charging him with fraudulently using some of the secret project money to finance real estate deals.

"He is anxious to prove that he did nothing against the interests of the South African people," Harrison said, "and that he and Mulder and Van den Bergh were not alone, that they did have the Cabinet's approval."

Dimbleby and Harrison said they first approached Rhoodie "through a third party" many weeks ago. They had previously dealt with Rhoodie while he was still the top civil servant in South Africa's Information Ministry and they were filming an awardwinning BBC television documentary, "The White Tribe," on the Afrikaners who run South Africa.

When Rhoodie first asked for money for an interview on the influence-buying scandal, Dimbleby said, "We pooh-poohed the notion. We told him nobody would pay it."

Then, according to Dimbleby and Harrison, word got around that the BBC had contacted Rhoodie. Two weeks ago two South Africans, Van den Bergh and businessman Josias Van Zyl, met with Rhoodie in Paris to persuade him not to release information that would hurt South Africa. After the two men returned to South Africa, their passports were confiscated without explanation, preventing them from meeting with Rhoodie again.

In Johannesburg, Van Zyl said he was canceling the deal "because of the repeated attacks on me by the government and certain sections of the press," United Press International reported.

["After the agreement has been canceled, Dr. Rhoodie will be free to do whatever he likes with the tapes and the documents he has," Van Zyl said.]

Subsequently, Dimbleby and Harrison said, it was apparent that "something had changed Rhoodie's attitude." Money was not longer an issue and he agreed to an interview.

Last Staturday, they met Rhoodie in a European city outside Britain and, after switching hotels several times, talked with him in a room the BBC secured "in a luxury hotel" for the interview.

"He looked remarkably fit for a man on the run," Dimbleby said of Rhoodie, a tall, handsome man known for smart clothes and expensive living. "He seemed almost confident."

While the BBC program was being readied for broadcast, two lawyers from the South African government commission investigating the scandal were in London trying to interview British residents believed to have been involved in an effort to use a British publishing group to disseminate South African progaganda.

South African Prime Minister Botha has extended the commission's tenure and asked it to go beyond its December report to "investigate and evaluate political culpability of the government" in the scandal. The commission's final report, due May 31, is still not expected to include evidence it considers detrimental to South Africa's security or relations with other nations.