Virginia Gov. Charles S. Robb's campaign fund-raisers collected more than $50,000 in undisclosed contributions after his 1981 election and recently transferred the money into a political action committee set up in part to fund the Democratic governor's political travels.

Robb's campaign committee, "Robb for Governor," two weeks ago transferred $96,760 into the account of "Virginians for Good Government Inc.," a newly formed PAC created with Robb's approval by state Del. Alson H. Smith (D-Winchester), the governor's chief fund-raiser.

More than half the funds came from campaign donations, mostly in the $250 to $1,000 range, that poured into the Robb campaign after his election but were never reported to the State Board of Elections because of an apparent loophole in Virginia elections law that does not require disclosure of such postelection contributions.

Smith and others today described those contributors as being mostly from "the business community," but declined to be more specific.

"Somebody didn't get on the boat before it got out of the dock," said Smith when asked about the contributions. "It just means they wanted to contribute but they forget until after the election."

Smith and a Robb spokesman both emphasized the governor's campaign committee never was under any obligation to report the contributions, a statement that was supported by a spokesman for State Attorney General Gerald L. Baliles. "We've spent hours being sure we were doing it to the letter of the law," Smith said.

Others, however, criticized that interpretation. "It definitely violates the spirit of the law," said State Sen. Ray Garland (R-Roanoke). "These were certainly political contributions and they should have been reported as such . . . . Coming after the election, they come very close to being a tip or a gratuity."

"People deserve to know where the money came from," said Gordon C. Morse, director of the state Common Cause chapter. "It only places a degree of suspicion not to disclose it . . . . This just points up how many holes there are in the present election law."

Robb press secretary George Stoddart said the governor would have "no objection" to disclosing the contributions. But, Stoddart added, Robb is "not going to unduly burden a busy accountant today."

Virginia's election laws long have been viewed by critics as weak and ridden with loopholes that allow thousands of dollars in business, labor and other special interest contributions to go undisclosed. Unlike federal election law, Virginia's law allows direct corporate and labor funds to be used in political campaigns, provides no mechanism for review of campaign reports, or authority to investigate violations.

In addition, the state law does not specifically require any reporting by political committees 30 days after an election if that committee does not have an outstanding debt. Robb reported receiving about $294,000 contributions from coal, real estate and other interests after his Nov. 2 election through his final Dec. 15, 1981 campaign report. It was after that date that the $50,000, including $10,000 from the Virginia Democratic party, came in.

The idea for "Virginians for Good Government Inc." apparently came after Robb's November 1981 election victory when he and his aides discovered that his campaign ended with a $30,000 surplus. After Robb asked campaign accountant Anthony Barone and Winchester lawyer Lewis M. Costello to research the law, they devised the idea for the PAC as a means of defraying Robb's political expenses, according to Stoddart.

"If you wanted to pay for travel for the governor, there would be a source of funds to pay for the airplane, if it was clearly not a gubernatorial function," Stoddart said.

Robb, who has been mentioned as a vice-presidential candidate in 1984, campaigned for Democratic candidates around the country last summer. Those trips were paid for by state Democratic parties and candidates for whom Robb was traveling, Stoddart said. None of the leftover campaign funds or PAC monies were used to pay for those trips, he said.

The PAC funds cannot be used to pay for a Robb trip on behalf of a candidate for federal office, Smith said, because most of the monies were not collected in compliance with federal elections law. If Robb campaigns for an outside state candidate, such as a governor's race in North Carolina, the PAC funds might be used, Smith said.