Democratic Party insiders have accused the FBI of trying to scuttle Hillary Clinton’s bid for the White House after more damning documents were released on Wednesday (AEDT).

The FBI released documents from a 2001 investigation which found no wrongdoing in then-US President Bill Clinton’s decision to pardon fugitive billionaire Marc Rich.

The decision was controversial at the time because Mr Rich’s wife had donated $US1 million to the Democratic Party. The documents released on Wednesday did not demonstrate that Mr Clinton had been cleared.

That release followed the FBI’s announcement on Sunday that it would re-open an investigation into Hillary Clinton’s private email server.

After Sunday’s development, the FBI obtained a warrant to search the laptops of disgraced former congressman Anthony Weiner and his ex-wife and Mrs Clinton’s close aide, Huma Abedin.

Angry Democrats have lambasted the FBI and its director James Comey for showing bias against Mrs Clinton with under a week to go until the November 8 election.

“Your actions in recent months have demonstrated a disturbing double standard … with what appears to be a clear intent to aid one political part over another,” Democratic heavyweight Harry Reid wrote in a letter on Monday.

Mrs Clinton remains ahead of Republican candidate Donald Trump in the polls, but the lead has dramatically narrowed. In fact, an ABC/Washington Post poll has Mr Trump ahead by one point.

Why release it all now?

There are some colourful explanations being offered.

Notorious conservative commentators Rush Limbaugh and Sean Hannity claim the FBI investigation was re-opened and details about Mr Clinton released to distract the world from what is to come from Wikileaks.

They believe Wikileaks is preparing to unleash damaging information on Mrs Clinton before next Tuesday’s election.

One of their allies, Fox News’ Bill O’Reilly, alleged rogue FBI agents would have leaked that the investigation was re-opened, forcing Mr Comey to act anyway.

But former Democratic strategist-turned-current commentator James Carville claimed the FBI’s actions were the result of Russian and Republican collusion.

“This is in effect an attempt to hijack an election,” Mr Carville told MSNBC. “It’s unprecedented … the House Republicans and the KGB are trying to influence our democracy.”

Meanwhile, rank and file Democratic Party supporters point to the fact that Mr Comey was formerly a Republican, meaning he is trying to aid Mr Trump.

In his letter to Mr Comey, Mr Reid echoed those sentiments by claiming: “You possess [unreleased] explosive information about close ties and coordination between Donald Trump, his top advisors, and the Russian government.”

More sensible explanations

United States Studies Centre Associate Professor Brendan O’Connor told The New Daily that one reason for the FBI’s recent actions toward Mrs Clinton was so it did not seem biased.

“There has been a fight in the FBI triggered by those who think Comey wasn’t hard enough on Clinton in the middle of the year,” Assoc Prof O’Connor said.

“If it had come out post-election that this was suppressed it would lead to a lot of criticism by Republicans, and Trump could claim the election was rigged.”

He said that Mr Comey had been accused of mishandling the investigation into Mrs Clinton’s use of a private email server, which cleared her of any criminal wrongdoing in mid-2016.

But that isn’t the only theory on why Mrs Clinton has been seemingly targeted by the FBI.

Announcing the investigation re-opened now to avoid bias or being accused of suppressing information after the election was given in a supposedly leaked FBI memo obtained by Fox News.