His comments follow allegations by a senior IOC official, Marc Hodler, about a major votes for cash corruption scandal.

IOC chief Juan Samaranch shocked by allegations

Mr Hodler says cities bidding to hold the games have been offered votes en bloc in return for bribes of up to a million dollars.

IOC head Juan Antonio Samaranch said the crisis was as serious as the political boycotts of the 1980s and Ben Johnson's drug scandal at the 1988 Seoul Games.

Claire Doole: Most serious allegations made by an Olympic official

And he promised the matter would be investigated by a panel already looking into separate corruption allegations over the Salt Lake City Olympic bid.

"If we have to clean, we will clean,'' he added.

"If it is necessary, we will expel members if this (investigation) commission feels these members are guilty.''

He also said the IOC may consider changing the way host cities are picked in an effort to eliminate possible corruption.

'At least one in 20 members corrupt'

On Saturday, Mr Hodler - an IOC executive board member - said agents had approached cities hoping to hold the games and offered to sell committee members' votes if the bid was successful.

Olympic official Marc Hodler: "I've been muzzled"

He alleged there had been abuses in voting for the 1996 Atlanta Games, the choice of Sydney for the 2000 Olympics as well as Salt Lake City for the 2002 Winter Olympics.

Mr Hodler, an IOC member since 1963, said a group of four people, including one IOC member, had been involved in promising votes for payment, although he would not identify them.

He thought 5 to 7% of the IOC's 115 members were open to bribery.

'Gagged'

Mr Samaranch's promise to investigate the bombshell allegations came after Mr Hodler said he had been ''muzzled'' by the president.

"I'm not saying anything - by presidential order," Mr Hodler told reporters as he left an executive board meeting.

Correspondents say the accusations are by far the most serious ever made on record by a leading Olympic official.

A representative of the committee said its members had worries about the work of agents who offered services to cities bidding to host the games.

"We have been concerned for some time by what seems to be the development of a professional class of Olympic agents offering services to bid committees," said IOC Vice-President Dick Pound.

"We are going to find out as quickly as possible what truth there is behind these allegations.''

Mr Pound said the IOC knew of the four agents but had no proof against them.

But he said that the bidding cities for the 2006 Winter Olympics had been ordered to stay away from them.