WASHINGTON (NYTIMES) - US President Donald Trump plans to pardon Mr I. Lewis Libby Jr, who as chief of staff to vice-president Dick Cheney was convicted of perjury in connection with the leak of a CIA officer's identity, a person familiar with the decision said on Thursday (April 12).

Mr Libby's case has long been a cause for conservatives who argued that he was a victim of a special prosecutor run amok, an argument that may have resonated with the President.

Mr Trump has repeatedly complained that the special counsel investigation into possible cooperation between his campaign and Russia in 2016 has gone too far and amounts to a "witch hunt".

Mr Libby, who goes by Scooter, was convicted of four felonies in 2007 for perjury before a grand jury, lying to FBI investigators and obstruction of justice during an investigation into the disclosure of the work of Ms Valerie Plame, a CIA officer.

President George W. Bush commuted Mr Libby's 30-month prison sentence, but refused to grant him a full pardon despite the strenuous requests of Mr Cheney, a decision that soured the relationship between the two men.

A pardon of Mr Libby would paradoxically put Mr Trump in the position of absolving one of the chief architects of the Iraq War, which Mr Trump has denounced as a catastrophic miscalculation. Plans for a pardon were first reported by ABC News.

Critics of Mr Trump quickly interpreted the prospective pardon as a signal by the President that he would protect those who refuse to turn on their bosses, as Mr Libby was presumed not to have betrayed Mr Cheney.

Mr Trump has not ruled out pardons in the Russia investigation.

Mr Libby's prosecution became a symbol of the polarising politics of the Iraq War during the Bush administration.

Ms Plame's husband, Mr Joseph Wilson, was a former diplomat who wrote an op-ed article in The New York Times accusing Mr Cheney of ignoring evidence that argued against the conclusion that Iraq was actively seeking to build nuclear weapons.

To undercut Mr Wilson's contention, administration officials told reporters that he had been sent on a fact-finding mission to Niger because his wife worked for the CIA.

But federal law bars the disclosure of the identities of CIA officials in certain circumstances and the leak prompted a special prosecutor investigation.