MOSCOW, Feb 9: Speculation mounted in Russia on Monday over what had happened to a presidential candidate who is backed by an exiled tycoon and Kremlin critic and has mysteriously gone missing five weeks before the election.

Some suggested that the disappearance of Ivan Rybkin, whose campaign is financed by Boris Berezovsky, the controversial self-exiled tycoon and President Vladimir Putin's political foe, was staged as a publicity stunt.

Rybkin went missing after he left his apartment in Moscow on Thursday evening and news of the 57-year-old's disappearance did not become public until the weekend.

On Sunday Moscow police began a search for the former parliamentary speaker who was seen as having little hope of winning the March 14 election. The story was splashed across the front pages of most Moscow newspapers on Monday, as observers speculated what could have happened to the ally of Kremlin's most vociferous critic.

Some suggested that Rybkin's disappearance was a publicity stunt organized by Berezovsky ahead of the elections. "I am 99 percent certain that this is yet another political stunt organized by Berezovsky," the Interfax news agency quoted Gennady Gudkov, a deputy from the pro-Kremlin United Russia party, as saying.

Central election commission chairman Alexander Veshnyakov said in televised comments over the weekend that he had his "own version" of what had happened to Rybkin, but he did not want to publicize it.

The Moscow prosecutor's office said on Monday that it had opened a murder inquiry into the case, but in a highly unusual move, withdrew the statement an hour later, saying it did not have enough evidence for such an investigation.

The reversal apparently came at the request of the general prosecutor's office. "The criminal investigation was opened too early," an official with the general prosecutor's office was quoted as saying by news agencies.

Prosecutors on Monday also questioned Rybkin's wife as part of the investigation. News of Rybkin's disappearance broke after he registered on Saturday as one of seven candidates in a presidential vote which Putin is widely expected to win. -AFP