The heavily redacted 129-page document concerns the pardon of Marc Rich, a Swiss-based financial trader who was indicted in 1983 but evaded prosecution. 

The documents show that his ex-wife, Denise Rich, is a wealthy Democratic donor who pledged $450,000 (407,000 euros). Some of the donations went to the William J. Clinton Presidential Foundation, the predecessor to the Clinton Foundation, according to the document.

In a controversial move, Rich was pardoned on the last day of Bill Clinton's presidency in 2001.

An FBI investigation was launched into the pardon later that year and closed in 2005 without charges. Rich died in 2013.

"It appears that the required pardon standards and procedures were not followed," the FBI document from February 2001 said. While Denise Rich's name is redacted from the files, it indicates that she "has been a major political donor to the Democratic Party, and these donations may have been intended to influence the fugitive's pardon."

The case fell under the watch of current FBI Director James Comey, then a prosecutor. Comey is currently under firefrom Democrats after notifying Congress on Friday, just days before the presidential election, of the bureau's decision to reopen its investigation into Hillary Clinton's use of a private email server while she was secretary of state. In July, Comey had determined that Clinton has mishandled classified information but did not recommend charges be brought against her or her staff.

The Democratic camp has questioned the FBI's decision to release the documents ahead of next week's election. "Absent a Freedom of Information Act (FOIA) litigation deadline, this is odd," Hillary Clinton's spokesman Brian Fallon tweeted. "Will FBI be posting docs on Trumps' housing discrimination in '70s?" referring to accounts concerning a 1973 federal housing discrimination lawsuit against the Republican presidential candidate and billionaire real estate mogul, Donald Trump.

The FBI said posting the documents was common procedure under FOIA guidelines and laws. Documents requested three or more times were made public "shortly after they are processed."

The Marc Rich documents "became available for release and were posted automatically and electronically to the FBI's public reading room in accordance with the law and established  procedures," the FBI said.

The agency also indicated that the document was a "preliminary" release, meaning it could be followed by more text.

White House spokesman Josh Earnest said he was unaware of anyone at the White House being consulted ahead of the release. Speaking to reporters traveling with President Barack Obama to Columbus, Ohio, on Tuesday, Earnest said: "I've not spoken to anybody who has any awareness of being consulted about that material before it was released."

dm/jm (AP, AFP)