In a bizarre twist to Russia's presidential campaign, a candidate who disappeared last week resurfaced Tuesday in Ukraine and returned home, saying he was surprised by the fuss and may even drop out of the race.

Ivan Rybkin (search), a critic of President Vladimir Putin (search), had been missing since late Thursday. He was last seen when he was dropped off outside his Moscow home, according to his wife and campaign staffers.

But his staff reported Tuesday evening that he had turned up in Ukraine, and Rybkin told the radio station Echo of Moscow, "I haven't disappeared anywhere."

"I decided not to listen to the radio and TV" for a few days, Rybkin said. "I decided to go to Kiev to visit friends."

Rybkin, 57, said he was "shocked" when he read Russian newspapers on Tuesday and saw that his absence was being given wide attention.

Rybkin returned by plane late Tuesday to Moscow, where he offered little further explanation. Instead, he dropped vague hints indicating that his absence was not an action of his own will.

"Such despotism is not like anything I have seen or experienced in 15 years of political life," Rybkin, wearing a fur hat and tinted glasses, said at Moscow's Sheremetyevo-1 airport.

"I am upset that all this made my daughter cry. But thank God I am here," Rybkin said.

Asked if he would consider withdrawing his candidacy, he said, "Yes, I am considering it." He did not say why.

Rybkin's wife and staff filed a missing-person report Sunday, the day after his candidacy for the March 14 presidential election was approved by the Central Election Commission.

"I have the right to two or three days of private life," Rybkin was quoted as saying by the Interfax news agency.

"Last week, I decided to take a break from the fuss around me. I left fruit and money for my wife, who now is occupied with the grandchildren, but didn't say anything to her, changed my jacket, got on the train and left for Kiev," he said, according to Interfax.

Rybkin was a national security chief under former President Boris Yeltsin (search), the ex-speaker of Russia's lower parliament, a participant in failed negotiations with Chechnya's rebel leadership in 2002, and a close associate of one of Putin's most vocal foes, self-exiled tycoon Boris Berezovsky.

While the mystery deepened, Russian political observers suggested several possibilities: that his disappearance was staged as a political gimmick, that he fell victim to intrigues within the Berezovsky-funded Liberal Russia party, or that he was targeted in a politically motivated attack by the Russian security services.

Prosecutors opened a murder investigation into Rybkin's disappearance Monday -- and then immediately closed it, citing a lack of evidence. Hours later, a lawmaker declared that friends in the security services informed him that Rybkin was found "alive and healthy" at a resort outside Moscow. But police and Rybkin's lawyer, Marina Savateyeva, denied that.

Liberal Russia leaders have said it would be unlike Rybkin to stage his disappearance as a public-relations move, as some Berezovsky critics had suggested.

A longtime critic of Russian security services, Berezovsky pointed the finger at them again, hinting in an interview published Monday in the daily Kommersant that they know something about Rybkin's disappearance.

Berezovsky told Echo of Moscow on Tuesday that he had spoken to Rybkin after he turned up and that Rybkin told him that he had been tired and went to Ukraine to visit friends.

He said he told Rybkin that "it's cool to spend time with friends, of course, but the whole world has been standing on its ears for a few days."

Berezovsky, wanted in Russia on fraud and theft charges, has been granted asylum in Britain and lives there. He said he had always known Rybkin to be a "very responsible" person and added that "if it turns out that this was an escapade, then [Rybkin's] political career is over."