The increasing tension within the international sports community brought on by the U.S. boycott of the Moscow Summer Olympics is casting a dark shadow over this city's plans to host the 1984 Games.

Over recent weeks, top Olympic officials from the Soviet Union, Europe and Mexico have openly suggested the possibility of taking the 1984 Olympics away from Los Angeles. They see it as punishment for the U.S.-led move against the Moscow games in retaliation for the Soviet invasion of Afghanistan. Others, including some Los Angeles officials involved with the Games, fear the 1984 event could well be subject to a devastating retaliatory boycott by Soviet bloc nations.

"If those Games are boycotted in Moscow, you can just about forget the Games in 1984," said James Hardy, secretary of the Los Angeles Coliseum Commission and for 30 years a leading advocate of holding the competition here. "There are dark clouds on the horizon for our Games."

Political pressures stemming from the boycott have made planning for the 1984 Games "substantially more difficult," said Peter Ueberroth, president of the Los Angeles Olympic Organizing COMMITTEE (LAOOC), a private group. Ueberroth recently traveled to an International Olympic Committee meeting in Switzerland and won assurance that the Games would remain as planned in Los Angeles from Lord Killanin, IOC chairman.

"There is a natural fear and uncertainty coming out of the Olympic Games and the boycott. But the Olympics have survived two world wars and I think will do all right in the end," Ueberroth said.

Killanin's pledge to LAOOC, awarded the Games in May, 1978, came in the wake of a suggestion made recently to Vitaly Smirnove, chief operating executive of the Moscow Olympics, and Soviet sports minister Sergei Pavlov that the American boycott poses a direct threat to the Los Angeles Games.

At a Moscow press conference last month, Smirnov announced Los Angeles could be stripped of the Games because of the Carter administration's "crude and even unprecedented interference in the Olympic movement."

In addition, a top IOC board member, Prince Alexander de Merode of Belgium, has recently suggested taking away the Games from Los Angeles in order to avoid retaliatory boycott by the Soviet bloc. Removal of the Olympics from Los Angeles has also been endorsed by Mario Vasquez-Rana, president of the Mexican Olympic Committee and head of the world-wide Association of National Olympic Committee.

Ueberroth dimissed the possibility that Los Angeles could lose the Games or would even be subject to a Soviet bloc boycott. He maintained the Soviet threats were merely a ploy to pressure the United States to abandon the planned Moscow boycott.

"The Russians will come here," Ueberroth said. "They dominate the sports games and they can't pass it up. They'd rather boycott their own Games. Sports is a religion to them."

Ueberroth also sharply denounced Vasquez-Rana for maintaining that the Games should be moved. He said Vasquez-Rana was simply trying to curry favor with the Russians, with whom he is working on a program to help send Latin athletes to the Moscow Games.

Despite repeated assurances by both Ueberroth and Killanin concerning the 1984 Games, some local leaders such as Los Angeles City Councilman Ernani Bernardi and coliseum commission secretary Hardy feel a Soviet counter-boycott of the Los Angeles event is likely.

"There's a good chance of an East bloc boycott," said Hardy, whose facilities would play a key role in the 1984 Games. "It would remove most of the good competition. We'd lose a lot of our luster."

Others with long experience dealing with the Soviets agree with the assessment that the Russians are hardly likely to turn the other cheek following a humiliating American-led boycott of their Games.

"If we don't show, the Russians won't show," said Stan Blum, who successfully negotiated with the Soviets for the North American licensing and merchandising rights for the 1980 Games. "The Olympics will not be the Olympics without both the United States and the U.S.S.R. People won't come to see Canada play. The 1984 situation is not very stable."

Blum and other Americans with business interests in the Moscow Games have been barred from exercising their agreements as a result of Washington's wide-ranging sanctions against Moscow following the invasion of Afghanistan. This experience led at least one potential Olympic sponsor, Adidas sportswear company, to shy away from its plan to help sponsor the Los Angeles Games.

"There's a growing feeling we don't want to participate in those Games," said Bart Stolp, general manager of Adidas USA. "The things happening with the Russian Olympics have a real impact on 1984. The Games, the whole future of the Games, is in jeopardy."

Los Angeles officials have roundly criticized Adidas. Television producer David Wolper, a member of the LAOOC board, charged Adidas with pulling away from the 1984 Games because the company did not wish to offend Soviet bloc countries, with whom they have lucrative sports supplies contracts.

While conceding his company sells equipment to the Soviets and their allies, Stolp called his company's decision on 1984 a "sober one" and denounced Wolper's charges as "unfounded and untrue.