The ISU has urged its members to own up to any dealings they may have had with Alimzhan Tokhtakhunov, the man at the centre of the 'Skategate' scandal.
The US Attorney's office is currently investigating Tokhtakhunov, and the ISU has handed over all the files from its own inquiry to aid proceedings.
The Union sent an "urgent request" to its 73 member federations on Tuesday asking for further help with the investigation.
The statement read: "If any skating person has met, or been involved in any way with, or knows of others that have been involved with, the accused Russian person, Alimzhan Tokhtakhounov, that information should be reported.
"It could be important to the authorities."
Tokhtakhunov, who faces extradition to the US, has already been charged with conspiracy to commit wire fraud and influence the Salt Lake figure skating results through bribery.
Italian police, who arrested the 53-year-old, said he may have contacted up to six judges to help secure a gold medal for Russia's Elena Berezhnaia and Anton Sikharulidze.
A separate ISU probe resulted in three-year bans for French skating chief Didier Gailhaguet and the French judge at the centre of the scandal, Marie-Reine Le Gougne.
The biggest judging scandal in Olympic history erupted the day after the pairs competition, when French judge Le Gougne said she had been pressured to vote for the Russians. She later recanted.
As a result, duplicate gold medals were awarded to Jamie Sale and David Pelletier, the Canadians who finished second to Berezhnaya and Sikharulidze.