Soviet television censors, who yesterday banned a West German broadcast on the Olympics on the ground that it was "political," today barred the French ambassador to Moscow from making a traditional Bastille Day address to Soviet viewers because he mentioned the Soviet invasion of Afghanistan.

The censorship of Ambassador Henri Fromont-Neurice was a virtual rerun of the earlier action against U.S. Ambassador Thomas J. Watson Jr.'s proposed July 4 speech, which also mentioned Afghanistan. The Soviets have made clear they will not allow foreign envoys to make public statements about the invasion, which has deeply scarred Moscow's Olympics.

The censorship of Klaus Bednarz, Moscow correspondent for West Germany's ARD network, caught the International Olympic Committee by surprise. The Soviets refused to transmit a filmed report detailing Soviet political propaganda about its summer Games.

The 5 1/2-minute segment includes quotes from the "Little Book for the Party Activist," published last year.One quote from the book declares that the Games, set to open Saturday, pit "decadent capitalism" against "socialism, which is growing stronger every day."

Bednarz, 38, ARD correspondent here for three years, said a censor told him, "It is politics and not Olympics. You can only give material about the Olympics." Bednarz said the censor ignored the correspondent's protest that the film included statements by Soviet President Leonid Brezhnev, who has said the awarding of the Games to Moscow is a triumph for the Communist Party.

The IOC has no formal procedure for handling complaints of press censorship. A member of the IOC Television Commission, Lance Cross of New Zealand, said he had no knowledge of the ARD problem and that the commission has no plans to meet to discuss it.

Cross, a long-shot candidate to succeed Lord Killanin as IOC president in elections scheduled for this week, said the problem "most likely will be worked out" by the IOC Executive Board.

European officials, who have overall rights to Olympic broadcasts into Western Europe, have not yet taken up the matter with Soviet broadcast officials. There is some suspicion among resident foreign journalists in Moscow that the visiting broadcasters are not eager to face a confrontation with the Soviets on censorship.

Killanin himself admonished the press last week to cover sports, not politics. ARD is waiting to see if Eurovision, of which it is a member, raises the question with the Soviets before taking any steps of its own.

Bill Ward, senior Eurovision administrator for the Moscow Games coverage, tonight told Western news agencies that this kind of editorial dispute ". . . is the responsibility of a member organization to take up with Gosteleradio." It was unclear whether ARD would press further in what could become a test case for Soviet handling and control of the Western television groups here. Nikita Khrushchev did away with direct censorship of the foreign writing press nearly 20 years ago.

But there have been various incidents of "pulling the plug" by the Soviets on television transmissions they do not like. Seldom, however, have they explicitly said, as they did to Bednarz, that it was because of political objections.