Several months ago, Acting Gov. Blair Lee III's campaign staff recruited two Montgomery County attorneys for what was known as a "Venetoulis truth squad." They were assigned to examine the records and newspapers in Baltimore County and report back on whatever inconsistencies they could find between the rhetoric and public actions of gubernatorial opponent Theodore G. Venetoulis.

The "truth squad" report was delivered to Lee's campaign headquarters last month and then passed along to the Rosenbush Advertising Agency, the acting governor's public relations fir. The advertising agency sifted through the material and then sent much of it up to Manhattan. There, radio advertising producer Tony Schwartz incorporated parts of the "truth squad" report into five 30-second radio commercials.

Those five commercials went on the radio airwaves in Baltimore and Washington last week and sparked a controversy that has found Venetoulis complaining to the Federal Communications Commission, led to several radio stations withdrawing the ads, and left many observers wondering why an incumbent with an apparently comfortable lead would decide to run a last-minute negative media blitz.

Venetoulis, who has considered himtively clings to the bad political habits of Maryland's old guard."

Lee's strategists, on the other hand, said that the anti-Venetoulis commercials were justified and prompted by a belief that the image-conscious challenger was spreading untruths about his record as Baltimore County executive.

"We felt there was a lot of deception going on in his campaign," said Frank DeFilippo, one of Lee's media advisers. Added Blair Lee IV, the candidate's son and political aide: "It was a sense of frustration in part. I guess there was a feeling that the papers were not zeroing in on some of the hyprocrisy Ted was spreading around. The only medium available to us was radio."

Of the five critical commercials, two have been withdrawn. One of those charged that, during his first year as Baltimore County executive, Venetoulis asked for $1 property tax raise. In fact, he had sought a 9 cent increase that year. "It was a factual error and we don't know how it happened," said Blair Lee IV. "We do know that that information did not come from the truth squad."

DeFilippo said his agency was not to blame for the mistake. And Schwartz, the producer, said: "When there are factual errors, they are supplied by the campaign. I never want to use anything incorrect. I think from now on I ought to put it in the contract that the clent verifies the accuracy of the material."

The second commercial that the Lee camp was forced to withdraw implied that Lee had won the endorsement of the Baltimore Evening Sun, when in fact the paper endorsed Harry R. Hughes in the Democratic primary. The commercial read:

"When the Baltimore Evening Sun endorsed its candidate for governor, this is what it said about Acting Gov. Blair Lee. And we quote: 'Mr. Lee shows the hearing of a man personally honest and well above the financial and politicaly corruption which destroyed Marvin Mandel.' Good for you, Evening Sun . . ."

DeFilippo said that commercial was played by the radio stations by mistake. "It had been vetoed by Blair himself," he said. "But it was on a master reel with the other spots and the radio stations erred in playing it."

Another of the five anti-Venetoulis commercials, one that has not been withdrawn, begins with the words: "My momma used to say that when a fish grows rotten it stinks from the head. I'm sorry, but that makes me think of the executive head of Baltimore County, Ted Venetoulis," That ad, which is being played only on black-oriented radio stations, was heard by Venetoulis yesterday.

"How is that for a piece of high-level, issue-oriented campaigning?" asked Venetoulis, who said the ad "debases the whole public campaigning process."

DeFilippo and his boss, Louis Rosenbush, disagree. They think the fish-head ad, in Rosenbush's words, "is fantastic, first-class." Schwartz said the imagery came from an "old folk saying" and that he was responsible for it. "My other-in-law says it all the time," said Schwartz. "It means that if something's rotten, you blame the person in charge."

The decision to run the anti-Venetoulis radio commercials were made at a session held on August 30 at Rosenbush's Pikesville office attended by Rosenbush, DeFilippo, Blair Lee IV, campaign manager Joseph Anastasi, consultant Joseph Napolitan and the acting governor.

Lee personally heard the ads and approved all but the one implying the Sun endorsement.

A few days before that meeting, DeFilippo said in an interview that "we're always prepared to do negative ads but in this race they don't appear necessary." And Napolitan, in his book "The Election Game and How to Win It," has written: "If it can be avoided, except in special circumstances, I never let my candidates use the media to deliver negative personal messages."

"These ads," DeFilippo said yesterday, "are not negative information. They're positive information used against a perst a person. We're talking about a guy (Venetoulis) who is promising taxpayer rebates, but who had surpluses in Baltimore County every year and not once delivered a rebate."