Juan Antonio Samaranch was last night forced to accept that unless he quickly resolves the Olympic movement's current crisis, it faces a massive financial loss.

David D'Alessandro, president of the key Olympic sponsor, John Hancock, said his company was cancelling negotiations with American television network NBC for $20 million in advertising until the International Olympic Committee (IOC) cleaned its act up.

"We're not going to buy a nickel of advertising on NBC until we are confident the IOC is going in the right direction," he said. "Each day they lose a bit more credibility. It's clear the leaders want to wake up and find this has all gone away and they have their club back."

D'Alessandro's move came after an internal ethics investigation published in Salt Lake City implicated another 10 IOC members in the cash-for-votes 2002 Winter Games scandal. The biggest name to be embroiled in the affair is Phil Coles, a member of the Sydney 2000 organising committee. It is alleged he and his family made four holiday trips to the United States, staying in expensive hotels and enjoying excursions. One of those was to the Super Bowl, costing the Salt Lake organisers $19,500.

Five members have already been suspended and another four forced to resign as a result of an IOC investigation last month. Richard Pound, the Canadian lawyer heading the IOC inquiry, said his six-member commission would examine the Salt Lake City ethics committee findings before he reports to the IOC session in Lausanne on March 17th.

D'Alessandro hopes withholding advertising will persuade NBC, the single biggest sponsor of the IOC with a $3.57 billion contract, that they must force the committee to make changes, possibly even forcing Samaranch to step down as president. "NBC tells them to change, you don't think the IOC will listen?" he said. "What are they going to do, go find someone else?"

It was a further blow for Samaranch, coming the day after the Dutch Crown Prince Willem Alexander announced he was suspending his membership of the IOC until he was satisfied the body was taking adequate steps to stamp out corruption.

Sydney's attempts to shore up flagging support from sponsors and the public to ensure the 2000 Games are a success are beginning to be seriously undermined by the Salt Lake City affair. The revelation that Coles was among the new members implicated was a devastating blow.

Coles insisted he was not guilty of any wrongdoing, but stood down from the Sydney organising committee until an IOC inquiry had been completed. In a further bid to retain the integrity of the Sydney Games, Australia's Olympics Minister Michael Knight agreed to launch an investigation into its own campaign.

Last month the Australian Olympic Committee president, John Coates, admitted he gave the Kenyan and Ugandan IOC members $35,000 on the eve of the 1993 vote when Sydney beat Beijing by two votes.