WASHINGTON (AP) _ A Soviet diplomat said Friday a former Soviet official who defected in 1982 and his family are being held by American authorities against their will, and he accused the United States of a ''flagrant violation'' of human rights.

The State Department denied the allegation, saying the family is free to do as it pleases.

The case involves Anatoly Bogaty, former first secretary at the Soviet Embassy in Morocco, who, according to the State Department, came to the United States with his family after his defection five years ago.

Soviet Embassy minister-counselor Eugene Kutovoy told a news conference that on Sept. 15 the embassy received a telephone call from Bogaty's wife, Larissa, who in a ''very passionate appeal'' asked it to help her return to her homeland.

Kutovy added that Mrs. Bogaty left a telephone number where she could be reached. Later, when embassy officials tried to reach her, Kutovoy said, the number did not work and appeared to be disconnected.

Since that time, Kutovoy said, all attempts to get in touch with Mrs. Bogaty or with members of the family have not succeeded.

He said, referring to the Bogatys, that the embassy would like to hear from ''the horse's mouth what their decision really is.''

''What we have here is a flagrant violation of basic human rights.'' Kutovoy concluded. ''While claiming that they do not hinder the return of the Bogaty family to the Soviet Union, the United States authorities, in reality, are delaying settlement of this issue under false pretext.''

''It is absolutely clear that this position is in stark contradiction with the numerous pronouncements of the United States authorities on their commitment to the respect for human rights and the existing norms of relations between civilized nations,'' he said.

Kutovy also said he did not accept the State Department description of Bogaty as a defector. He said the former diplomat disappeared ''under undetermined circumstances'' on Sept. 22, 1982.

Asked about Kutovoy's allegations, State Department deputy spokeswoman Phyllis Oakley said the family is free to contact whomever they wish and to travel where they please.

Another official said Mrs. Bogaty has had dificulty over the years deciding whether she wants to remain in the United States or to go back to Russia.

''She keeps changing her mind,'' the official said, insisting on anonymity.