Paul T. Bannai, who oversees the Veterans Administration's extensive national cemetery network, has taken numerous trips at government expense during the past 16 months that combined VA business with his personal and private business interests.

Bannai, who earns $67,200 a year as director of the VA's Department of Memorial Affairs, has charged the government for a trip to a Veterans of Foreign Wars reunion where he joined his World War II buddies. During business trips charged to the government, he also visited his home during the Christmas holidays and took time off to play golf in South Carolina with several VA officials who paid all their expenses out of their own pockets. In both of these instances, the government paid for Bannai's travel but he paid for his personal expenses at home and on vacation.

Bannai's federally funded travels also allowed him to attend at least two board meetings of a California bank, on whose board he serves, and to visit relatives and friends in Oregon and Illinois.

In an interview, Bannai said that he had conducted personal business and had taken vacations during some of the 26 business trips which he has charged to the government since he was hired in late 1981. Bannai said that his private and personal business actions were scheduled only after the official VA business trips had been mapped out.

Bannai's travels fall into a gray area in government travel, according to officials at the General Services Administration, General Accounting Office and Office of Government Ethics.

"It's a bit like asking which came first, the chicken or the egg," a GAO official said. "If the official travel was already planned, then there probably wasn't anything improper about conducting personal business, too . . . . The question is: 'How do you know?' "

Bannai's most frequent destination has been Los Angeles, according to his travel vouchers. It also is the site of his home, his insurance and realty business and where his wife, a college professor, lives.

Last July, in an excursion typical of his travels, Bannai charged the government $840.72 for a trip to the annual convention of the Disabled American Veterans.

The convention began in Las Vegas on a Monday. Bannai flew to Los Angeles three days ahead of time. Friday he attended the monthly meeting of the Republic Bank's board of directors, on which he serves. He then spent the weekend at his home. He did not charge the government for his expenses in Los Angeles.

Sunday he flew to Las Vegas. He spent one day at the DAV convention, then flew back to Washington.

Bannai said he decided to fly to Los Angeles because he wanted to visit the VA cemetery in Riverside, Calif., not because of the bank board meeting.

"If I'm in town, I try to attend the bank meetings," he said. "I have tried to resign from the bank several times, but they always refuse . . . ."

Although officials of the Riverside cemetery kept no records of Bannai's visits, the cemetery manager said Bannai had visited the facility several times.

In fact, Bannai's first government-financed trip was to the cemetery. He flew there Dec. 23, 1981, and stayed in California, visiting Riverside and other cemeteries until Jan. 4, 1982. That trip cost $623.71. Bannai did not bill the government for most of his lodging because he stayed at his home.

According to his travel vouchers, Bannai listed trips to Riverside and other cemeteries in the Los Angeles area as the justification for five of his six trips to Los Angeles.

Asked why he visited Riverside cemetery so often, Bannai replied: "That is where I plan to be buried . . . . I have a special interest in it."

The only trip that Bannai made to Los Angeles that didn't involve Riverside cemetery was in February, 1982, when he charged the government $573.04 to attend what he described as a four-day "Veterans of Foreign Wars Convention."

According to VFW officials, what Bannai actually attended was the annual California reunion of 14 VFW posts whose membership is comprised largely of Japanese-Americans.

Bannai, who belongs to one of the posts, performed no official functions at the convention. When he paid his registration fee, Bannai identified himself as a VFW post member. In an interview, he said the trip was a valid government expense because he was "formally invited to attend as a VA official."

"We invited him . . . . We always invite all officials at the VA," said Robert Wada, who invited dignitaries to the reunion. Wada added that he assumed Bannai came because he is a member of a California post.

This February, Bannai irritated some of his VA peers by charging the government $232.75 for travel to Florence, S.C. Each year, several VA officials have gone to a South Carolina resort to play golf and "simply get away," a VA official said.

All of the VA employes, including Bannai, declared annual leave to attend the outing. Bannai later charged his travel expenses to the government because he said he visited VA facilities on the way home from the golfing holiday.