In the final round of voting for the 2006 World Cup on July 6, 2000, Dempsey, who died in 2008 at the age of 87, ignored the reported Oceania confederation instruction to vote for South Africa and abstained, allowing Germany to win a 12-11 vote against South Africa.
On arriving back in New Zealand he told reporters he had been threatened by "influential European interests" that if he voted for South Africa there would be "adverse effects" for Oceania.
He denied he accepted bribes. ISL, which collapsed in 2001, was closely affiliated with world football governing body FIFA.
Former FIFA president Joao Havelange and his former son-in-law and Brazilian football supremo, Ricardo Teixeira, received millions of dollars in bribes from ISL for World Cup marketing deals, court documents from the Swiss investigation showed.
In total, ISL made payments of 138 million Swiss francs in bribes between 1989 and 2001, involving several FIFA officials.
Germany's Spiegel magazine reported 10 days ago that the German bid committee had a slush fund which was used to secure four crucial votes from Asian FIFA executives at the host nation election in 2000.
The money came from the private funds of former Adidas chief Robert Louis-Dreyfus.
The DFB has denied the existence of a slush fund and said no bribes were paid to secure World Cup votes.
The reports follows last month's release of a book by investigative journalist Andrew Jennings called The Dirty Game: Uncovering the Scandal at FIFA.
An extract from the book has been published in the Daily Mail and it alleges the 2006 World Cup went to Germany after Dempsey was bribed to abstain from the decisive ballot.
Anticipating the possibility of a 12-12 draw, the arrangement was that Charlie would leave the vote, go back to the Dolder Grand hotel and collect a briefcase left for him in the cloakroom. It contained US$250,000. A cab would rush him to the airport for the flight home.
After the vote Dempsey complained of "intolerable pressure" and later said this was in connection with attempts to bribe him. He and his family also received death threats.
There was at the time no evidence of Dempsey taking bribes but he soon resigned from the FIFA executive committee and as Oceania chairman.
Oceania Football Confederation (OFC) secretary general Tai Nicholas insisted Dempsey would not have accepted a bribe
"Having been involved in the meetings to decide OFC's voting preference at that time, I know that Charlie followed the mandate set out for him by the OFC executive committee," Nicholas said.
"Charlie was a wealthy businessman in his own right, having arrived in New Zealand from Glasgow in 1952 he went on to establish a successful building business.
"It seems absurd that he would take a bribe as the reports have indicated as he did not need the money.
"It is also disappointing that such an allegation has come seven years after Charlie passed away, as he is unable to defend himself."
