Soviet President Leonid Brezhnev was rumored today to have been hospitalized, but a Foreign Ministry spokesman said he had no information on the Soviet leader's health.

Brezhnev, 75, was reported by unofficial sources to have been admitted to the Kremlin hospital Friday on his return from a trip to Uzhbekistan, in Soviet central Asia.

The rumors about his failing health were started when Moscow television and the main newspapers failed to carry the customary photograph of his return.

The next day the rumors gained strength when it was announced unexpectedly that the scheduled visit Monday of South Yemeni President Ali Nasser Mohammed Hasani had been postponed. Arab diplomats said the initiative had come from the Soviet side, presumably because Brezhnev had been too fatigued to welcome the foreign guest as required by protocol.

Perhaps the most important piece of circumstantial evidence is the fact that Brezhnev's personal physician, Yevgeny Chazov, today suddenly canceled his scheduled visit to England where he was to have been a cochairman at an antinuclear conference in Cambridge. Chazov's office said he was ill.

The doctor was to have departed yesterday for England. The conference is scheduled to open Saturday. British sources said he advised the organizers today that he would not be coming.

Brezhnev's signature, however, has continued to appear regularly on various official statements. Tonight, his message of congratulations to Vietnamese Communist Party leader Le Duan on his reelection was the lead item in the Moscow television newscast.

There has been no reliable information about the state of Brezhnev's health. During the past few years he has undergone periodic bouts of poor health that occasionally kept him out of the public view for weeks.

His schedule during the past three weeks has been very busy and included two major speeches.

The Soviet leader appeared to be quite fit while addressing a trade union conference March 17. He made a major arms control speech at that time.

Last Wednesday, while visiting Tashkent, he delivered another major speech dealing with Soviet policies in Asia. The four-day trip to Uzhbekistan also involved tours of several major enterprises and talks with regional leaders. During his televised address from Taskhent, Brezhnev appeared tired.

As is customary here, Soviet officials refuse to discuss the question of Brezhnev's health, and an official explanation was not expected.

Tonight, police turned away cars seeking to enter a small street not far from the Kremlin walls where the entrance to the Kremlin hospital for dignitaries is located.

The Soviet leader has been ailing for some time. A heavy smoker throughout his life, he is said to suffer from emphysema. Those who have seen him personally in recent years have noted a slurring in his speech, presumably caused by problems with his jaw, and also hearing difficulties.

There was speculation here that the Soviet leader must have been affected by recent deaths of several of his close associates, including party ideologist Mikhail Suslov. Brezhnev was seen on television openly weeping during a funeral of an Army general who was his close friend.

Although Brezhnev was described by Western visitors who have had contact with him during the years as appearing noticeably older and less vigorous, his ailments do not appear to have diminished his political authority and influence.

In recent months, however, there have been rumors here touching on his family in connection with a corruption scandal.