A US Attorney's office "erroneously" sent a confidential court document to The Washington Post after the Post requested a different file, exposing that the newly-elected chairman of the Republican National Committee had his 2006 Senate campaign pay his sister's defunct company for services that were potentially never performed -- including $37,000 for "catering/web services" paid to her company 11 months after she filed to have it dissolved.

Federal agents have contacted Steele's sister, the chairman's spokesman told the paper. Former Steele campaign finance director Alan Fabian offered the information to the US Attorney's office as part of attempt to seek leniency for himself in another case.

"It is unclear how extensively his claims have been pursued. Prosecutors gave him no credit for cooperation when he was sentenced in October," the Post said.

Steele's spokesman, Curt Anderson, dismissed the charges.

'"It's from, what, a convicted felon? And it has no substantiation in fact," he said.

But Fabian's claims surfaced just as Steele begins his new role at the RNC, where he's responsible for stewarding hundreds of millions of party dollars. And they were apparently at least in part substantiated by documents Fabian produced to investigators. The Post also corroborated some of the claims.

In one allegation, Fabian says Steele's Senate campaign paid more than $37,000 to Brown Sugar Unlimited, a company run by Steele's sister, Monica Turner. Records show the expense being for "catering/web services," but Turner filed to dissolve her company 11 months before the payment was received.