Conrad Black, at one time a substantial shareholder in Fairfax Media and a long-time associate and political ally of Donald Trump, has been granted a full pardon by the US president.

He was sentenced to six-and-a-half years jail after being found guilty of fraud and obstruction of justice in 2007. Charged with swindling his Hollinger International publishing business of $US60 million, he was released after serving just over two years, but returned to jail for around a year after a judge ruled that he had not served sufficient time.

Black is a former owner of the Chicago Sun-Times and the London Daily Telegraph. He built up a stake in Fairfax Media (now part of Nine Entertainment) in the early 1990s.