Mohamed Bin Hammam, the president of Asian football, is being challenged for his seat by Sheikh Salman bin Ebrahim Al Khalifa, the president of the Bahrain FA.

Now the watchdog body of FIFA, the ethics committee, have been called in to investigate claims by Bin Hammam that the Olympic Council of Asia have offered grants to selected national football associations in Asia in return for securing their votes for Salman.

The complaint has been made by Australian broadcaster Les Murray, who is also a member of FIFA's ethics committee. As a result of the complaint, FIFA ethics committee acting chairman Justice Petrus Damaseb confirmed he is going to commence an investigation.

In his letter to Damaseb, Murray says: "I am compelled to report to you a matter which, in my view and the view of my FIFA ethics committee colleagues in Indonesia and Guam, requires investigation by the FIFA ethics committee.

"I have been given reliable information that there is a case of 'vote-buying' going on ahead of the election to appoint an AFC member to the FIFA executive committee. The information points to at least one high level football official being involved.

"In an interview with SBS, recorded on March 30, Mr Bin Hammam claimed that the Olympic Council of Asia, via its national Olympic committees, is offering cash grants to selected national football associations in Asia in return for securing their votes for Sheikh Salman."

Murray added that SBS had obtained "credible corroborating evidence to support Mr Bin Hammam's claims, including testimony from the president of a national football association in Asia who told us his organisation has received such offers."

Salman last week dismissed Bin Hammam's earlier accusations that he was being bankrolled financially by Korea's FIFA executive committee member Chung Mong-Joon.

Salman said: "I don't think I need the financial support of Dr Chung. I think I have the support of the Korean FA, this is very important and I have the support of Japan and other national associations, this is the right of each federation to support whoever they want.

"Why try to damage my reputation because I am running against him.

"I think that he has to concentrate on his campaign and what he will do for the AFC rather than talk about Dr Chung or anybody else."

Meanwhile, South Korea's football association today said they have themselves referred a remark made by Bin Hammam to FIFA's ethics and disciplinary committees.

Bin Hammam had said he would "cut the head off" his rivals - he later insisted he was using an Arabic expression similar to the English 'heads will roll'.

The Korean FA said the explanation was unsatisfactory and that one of their officials has travelled to FIFA headquarters in Zurich to file a complaint.

FIFA president Sepp Blatter urged all involved in the controversy to abide by the rules, and moral ethics of sport, ahead of the election.

Blatter said in a statement: "Football is a universal sport based on the fundamental principles of discipline and respect for opponents and the laws of the game as well as on the spirit of competitiveness and rivalry, underpinned by the values of fair play and ethics.

"These principles and values must be applied not only on the field of play, but also in the administration and governance of football, particularly in the area of sports politics. And, of course, this includes elections to the governing bodies of football.

"As president of FIFA, it is my duty to remind all members of the Asian football community of the importance of these values in the run-up to the election scheduled for May 8 for the vacant Asian seat on the FIFA executive committee and of the requirement to respect FIFA's statutes, principles and decisions, in accordance with the regulations governing world football."