Police questioned Prime Minister Tony Blair for a second time about allegations that political honors were traded for cash, the British leader's official spokesman said Thursday.

Blair was interviewed Jan. 26 as a witness and not under caution, Blair's office said. Police confirmed they requested details be kept secret for "operational reasons," but did not elaborate.

The prime minister was "interviewed briefly to clarify points emerging from the ongoing investigation," London's Metropolitan Police said in a statement.

"He was interviewed as a witness, not as a suspect, and cooperated fully," the statement said.

Police are investigating allegations that honors, including seats in the House of Lords and knighthoods, were given to individuals who loaned money to Blair's Labour Party or the main opposition Conservatives.

The British leader was questioned at his Downing Street office before he left London to travel to the World Economic Forum, in Davos, Switzerland, his office said.

"At the request of the police this was kept utterly confidential," the prime minister's spokesman told reporters at a daily briefing. He speaks to the media only on condition of anonymity.

The spokesman, who said Wednesday there had been no new police interview, said Blair's press and communications unit were not informed until late Wednesday.

"No doubt the police have their reasons," Blair's spokesman said. "This was kept extremely tight."

Police said the interview was "kept confidential for operational reasons," but refused to disclose details.

Blair's spokesman said the interview took less than 60 minutes and confirmed the prime minister was not accompanied by a lawyer. A notetaker was present, the spokesman said, but he could not confirm whether Blair was questioned by a uniformed police officer or by Deputy Assistant Commissioner John Yates, head of the inquiry.

However, Blair was not interviewed "under caution," meaning it is unlikely he is suspected of committing offenses.

Blair's chief fundraiser, Lord Levy, was arrested for a second time on Tuesday by police investigating the claims. Officers said he was detained on suspicion of conspiracy to pervert the course of justice, and later released on bail.

Three others arrested are Ruth Turner, Blair's director of government relations; Sir Christopher Evans, a biotechnology entrepreneur; and Des Smith, a government adviser.

Turner and Levy have both been questioned over conspiracy to pervert the course of justice allegations, prompting Scottish National Party leader Alex Salmond to ask Blair Wednesday if there had been a cover-up of wrongdoing.

Blair told Salmond at his weekly questions session that "for perfectly obvious reasons, that there is nothing I can say on this subject."

The leader's spokesman said Wednesday that Downing Street had "cooperated at all times with the police." He said any allegations of a cover-up needed to be backed with evidence.

Blair was first interviewed by police for 90 minutes on Dec. 14. He was the first serving British prime minister to be interviewed in a criminal inquiry.

He has acknowledged some supporters who offered loans were later nominated for honors, but has insisted that he did nothing wrong. Those candidates had been legitimate selections, allowed under rules to reward supporters for their service to a political party — rather than the general public, Blair's spokesman said.

"It is clear that this inquiry is going to haunt Tony Blair throughout his last months in office and beyond," said Edward Davey, a lawmaker and chief of staff for Liberal Democrat leader Menzies Campbell.