KUALA LUMPUR, Malaysia — The Malaysian opposition leader, Anwar Ibrahim, denied accusations of sodomizing a male aide and took refuge in the Turkish Embassy yesterday, saying he feared a government plot to assassinate him.

The sodomy accusations — made in a police complaint by a 23-year-old aide — revived memories of a similar accusation a decade ago that led to Mr. Anwar’s imprisonment and ouster as deputy prime minister, even though a court later exonerated him. Mr. Anwar accused the government yesterday of a conspiracy to thwart his rising political clout.

The startling developments provided a twist to Malaysian politics, which have been in turmoil since March 8 elections in which Mr. Anwar’s opposition coalition made unprecedented gains against the governing National Front coalition.

Mr. Anwar has since been vying to unseat the government, saying he is in a position to engineer enough defections from the Front.

In a statement posted on his Web log, Mr. Anwar said the opposition’s political comeback has put his life in danger.

“I have been told that my assassination has not been ruled out as means to subvert the people’s will and bring an end to the transformational changes taking place in Malaysia,” Mr. Anwar wrote on his blog from the Turkish Embassy where was holed up since early yesterday.

Mr. Anwar’s party said that he was not seeking political asylum but that the Turkish ambassador had offered him protection. Mr. Anwar is known to be a close friend of Turkey’s prime minister, Recep Tayyip Erdogan.