Steve Bannon, a prominent right-wing figure and former senior advisor to Donald Trump, was released from prison early on Tuesday after spending nearly four months behind bars and just a week ahead of the US election.

Bannon left a federal prison in Connecticut where he was serving time for a contempt of Congress conviction, several US media outlets reported.

"I'm not broken, I'm empowered," the 70-year-old told the New York Times outside the prison.

Bannon was convicted of defying a subpoena to testify before the congressional panel investigating the January 6, 2021 attack on the US Capitol by Trump supporters.

When he entered prison on July 1, he defiantly said he was "proud" to serve time "if it's what it takes to stand up to Joe Biden."

Much has changed in US politics since then, with Biden dropping out of the race and Kamala Harris replacing him as the Democratic nominee.

Bannon played a senior role in Trump's 2016 campaign and later served in the White House as chief strategist, leaving after seven months reportedly due to conflicts with other top staffers.

Though he no longer works officially for ex-president, he has continued to use his influence to get him back in the White House, mainly through his podcast "The War Room."

In 2020, he was charged with wire fraud and money laundering for taking for personal use millions of dollars contributed by donors for the construction of a border wall with Mexico.

While others were found guilty in the scheme, Trump issued a blanket pardon to Bannon before leaving office in January 2021, leading to the dismissal of the charges against him. (AFP)