Image copyright Reuters Image caption Conrad Black, who became Lord Black of Crossharbour, was known for his extravagant lifestyle

US President Donald Trump has signed a full pardon for former media mogul Conrad Black, who he describes as a "friend".

Black, 74, was convicted of fraud and obstructing justice in 2007 and jailed for more than three years in the US.

A White House statement described him as an "entrepreneur and scholar".

Canadian-born Black, who has British nationality, was released in 2012. Last year he published the book Donald J Trump: A President Like No Other.

The British peer once ran a media empire that included the UK's Daily Telegraph, the Chicago Sun-Times and the Jerusalem Post.

"Lord Black's case has attracted broad support from many high-profile individuals who have vigorously vouched for his exceptional character," a White House statement announcing the pardon said.

It said he had made "tremendous contributions to business, as well as to political and historical thought" and that, "in light of these facts", he was "entirely deserving of this Grant of Executive Clemency".

On Twitter, Black said when the White House had phoned him, he believed it to be a "prank" by his "friends in the British tabloid media".

Speaking on BBC Radio 4's Today programme, Black said he "should never have been charged" and that Mr Trump phoned him last week to announce his pardon.

Media playback is unsupported on your device Media caption The former media baron tells Today his conviction 12 years ago was "unjust"

Writing in Canada's National Post, which he founded in 1998, Black said Mr Trump "could not have been more gracious" and had offered to give evidence at his trial in 2007.

Mr Trump insisted that "the supportive things" Black said about him and the fact the two men had "known each other a long time" was not the reason for his pardon, Black wrote.

In 2015, Mr Trump tweeted an opinion piece by Black entitled Trump is the Good Guy, calling him "one of the truly great intellects and my friend", saying "I won't forget!".

In the opening chapter of the book, Black writes: "Like the country he represents, Donald Trump possesses the optimism to persevere and succeed, the confidence to affront tradition and convention, a genius for spectacle, and a firm belief in common sense and the common man."

Stripped of honour

Black renounced his Canadian citizenship when he became a British peer in 2001 but moved back to Canada following his release from a Florida prison.

In 2014 Canada stripped him of its highest honour, the Order of Canada, which was awarded in 1990 for a lifetime of achievement.

Image copyright Rex Features Image caption Conrad Black and Barbara Amiel at a fancy dress party at Kensington Palace in 2000

In 2007 Black was convicted of defrauding Hollinger International shareholders of $6.1m (£4.7m), by paying himself a tax-free bonus from the sale of newspaper assets without the approval of the company's board.

He had been forced out of the company by shareholders in 2003.

After his conviction, Black was sentenced to 78 months in prison. He then pursued a partially successful appeal, in which a judge cut his sentence down to 42 months.

Who else has Trump pardoned?

The White House has also announced a pardon for Patrick Nolan, a former Republican leader who spent more than two years in prison after pleading guilty to a racketeering charge.

Nolan told the Los Angeles Times he was "obviously very grateful" and "had hoped" to get a pardon. "There are a lot of other people that are incarcerated who would be better off at home with their family".

Speaking of his advocacy work for criminal justice reform, Nolan tweeted that he was "grateful that God used my time to open my eyes to injustice".

Critics have accused Mr Trump of using his powers of pardon to address what he believes are political wrongs.

In 2017, he pardoned ex-Arizona sheriff Joe Arpaio, who had been convicted of criminal contempt, after he defied a court order to stop traffic patrols targeting suspected immigrants.

Last year he issued a pardon to conservative writer Dinesh D'Souza, who was convicted in 2014 of violating campaign finance laws.

Other pardons have included Lewis "Scooter" Libby, former Vice-President Dick Cheney's chief of staff, who was convicted of lying about leaks to the media, and Jack Johnson, boxing's first black heavyweight champ, convicted in 1913 of taking his white girlfriend across state lines.