MOSCOW, May 6 (AFP) - A Russian MP has asked an eccentric regional leader to explain his behaviour after claiming on state television that he was visited at home by aliens in a UFO, media reported Thursday.

Kirsan Ilyumzhinov, head of the Buddhist Kalmykia region of southern Russia and president of the World Chess Federation (FIDE), announced without apparent irony on a high-profile chat show he had met the aliens in 1997.

In an equally bizarre twist, Andrei Lebedev, an MP for the nationalist Liberal Democratic Party, has now written to President Dmitry Medvedev raising fears that secret information could have been disclosed in the close encounter.

"I ask you to say if the head of Kalmykia has made an official report to the Russian presidency about his contacts with representatives of an alien civilisation," he said, quoted by tabloid Komsomolskaya Pravda and other media.

"Is there an established procedure of informing about such contacts by high ranking people who have access to secret information like Ilyumzhinov?

"And did he in the course of his seemingly innocent conversation disclose secret information?"

Ilyumzhinov had said in his comments, broadcast in late April, that the aliens appeared in a transparent tube on the balcony of his apartment in Moscow.

"I was reading my book, watching television and had almost fallen asleep. Then I felt that someone was calling.

"I would not have believed it, if I had not had three witnesses -- my driver, my minister and my aide," he said.

This is not the first time the chess-mad leader has spoken of extraterrestrial encounters. He had earlier claimed to have been shown round a UFO in 2001.

Ilyumzhinov has ruled Kalmykia since 1993. The Russian republic, which lies north of the Caucasus on the Caspian Sea, is the world's westernmost Buddhist region with a population of around 300,000.

Russia last month nominated him to stand again as president of FIDE, prompting derision from several top chess figures including former world champion Anatoly Karpov.