FIFA on Wednesday asked England's Football Association (FA) and a newspaper to provide evidence of fresh allegations of corruption at the top of world football, saying they were of "extreme concern".

The move followed widespread media reports in Britain on Wednesday which branded officials "sleazeballs" and "rotten to the core" a day after more claims were made against six decision-makers on FIFA's executive committee.

The secretary general of world soccer's governing body, Jerome Valcke, sent a letter to the FA asking for a report from former England 2018 chairman Lord David Triesman.

In testimony to a parliamentary hearing in London revealed on Tuesday, Triesman named four FIFA executive committee members who had requested cash and a knighthood in exchange for their votes in the 2018 World Cup ballot.

"In his letter to The FA, the FIFA Secretary General expresses the extreme concern of FIFA and the FIFA President (Sepp Blatter) at the latest allegations questioning the integrity of some FIFA Executive Committee members in connection with the bidding procedure for the 2018 and 2022 FIFA World Cups," a FIFA statement said.

Valcke asked for any documentary evidence "to be in a position to examine the situation thoroughly and with clear-sightedness".

He also called on the Sunday Times newspaper to submit any other evidence it had, especially on "a whistleblower who had worked with the Qatar bid".