US president Donald Trump has granted a pardon to former media mogul Conrad Black who was imprisoned for three years for defrauding investors.

Lord Black of Crossharbour, 74, is the former proprietor of the Daily Telegraph and a number of other world newspapers and was released from prison in the United States in 2012.

The president, then a candidate for the White House, called Lord Black “one of the truly great intellects and my friend” and said he “won’t forget” after the publication of an article in the National Enquirer about his campaign.

In response to the December 2015 tweet, Lord Black wrote: “Many thanks, Donald and all good wishes in helping to clean up the American government. Honored to be your friend.”

In a statement, the White House said: “In 2007, prosecutors alleged that Lord Black had committed several acts of mail fraud and obstruction.

“The Supreme Court of the United States, however, largely disagreed and overturned almost all charges in his case. He nevertheless spent 3.5 years in prison.”

Baroness Thatcher funeral
Henry Kissinger was among those who vouched for Conrad Black (Kirsty Wigglesworth/PA)

The statement added the case of Lord Black had “attracted broad support from many high-profile individuals who have vigorously vouched for his exceptional character”, including Sir Elton John and former US secretary of state Henry Kissinger.

“Consistent with his distinguished reputation for helping others, while in prison, Lord Black served as a tutor for 150 students, helping them achieve their educational goals,” it added

“In light of these facts, Mr Black is entirely deserving of this Grant of Executive Clemency.”

Donald Trump
Donald Trump signed the executive grant of clemency on Wednesday (Brian Lawless/PA)

Lord Black, born in Montreal, Canada, was the former head of Hollinger International, which once owned the Daily Telegraph, Chicago Sun-Times, Jerusalem Post and hundreds of community papers in the US and Canada.

He was ennobled as Lord Black of Crossharbour in 2001, having renounced his Canadian citizenship to become a Conservative peer.

His downfall came in 2007 when jurors in Chicago found him and other Hollinger International executives swindled shareholders out of more than six million dollars (then worth around £3 million) of their money.

The jury found Lord Black illegally received 3.5 million dollars (£1.75 million) of this as they convicted him of three counts of fraud and one of obstruction at the Dirksen Federal Courthouse in Chicago, Illinois.

He was convicted of three counts of fraud but cleared of a further six, with the jury of nine women and three men clearing him of charges of racketeering and tax evasion.

The jury had to consider 42 counts against him and his three co-defendants – John Boultbee, of Victoria, British Columbia, Canada, and Peter Atkinson, of Oakville, Ontario, who are both former Hollinger International vice presidents, and former corporate counsel Mark Kipnis, of Northbrook, Illinois – in a highly complex trial.

The prosecution said that the 60 million dollars came mainly from the sale of hundreds of Hollinger-owned US and Canadian regional newspapers between 1998 and 2001, in which the buyers paid large sums in return for agreements that Hollinger would not compete with the new owners.

Lord Black was granted bail pending an appeal against his conviction in 2010, with two of the fraud counts against him overturned in October of that year.

In addition to his business interests, Lord Black has written biographies on three American presidents – Franklin Delano Roosevelt, Champion Of Freedom; Richard M Nixon: A Life In Full; and, last year, Donald J Trump: A President Like No Other.

The publisher of the book on Mr Trump, Regnery Publishing, described the 256-page work as “Conrad Black, bestselling author of Franklin Delano Roosevelt: Champion Of Freedom and Richard M Nixon: A Life In Full, turns his attention to his ‘friend’ President Donald J Trump and provides the most intriguing and significant analysis yet of Trump’s political rise”.