The incoming Director of Public Prosecutions has a conviction for possession of cannabis, it has emerged.
Ken Macdonald was fined £75 for cannabis possession in 1971
Ken Macdonald was prosecuted when he was an 18-year-old student after sending 1g of the drug, worth 25p, through the post to a friend
The Attorney General's Office said it knew of Mr Macdonald's 1971 drugs conviction, and a separate speeding conviction in 2001, before he was appointed.
The drugs conviction earned the young Mr Macdonald a £75 fine and he was also ordered to pay £5 costs.
Last week's announcement that he would be the new head of the Crown Prosecution Service prompted allegations of "rampant cronyism" from senior Tories.
They were angered by the fact that the QC co-founded the legal chambers where Cherie Blair works.
After news of Mr Macdonald's convictions emerged, shadow home secretary Oliver Letwin said: "There may be public disquiet about the appointment of a chief
prosecutor who has himself been prosecuted in the past."
But he added: "We are more concerned about the fact that, as Michael Howard pointed out
several days ago, the government has nominated somebody who has very little by
way of experience of prosecuting ordinary criminals and who has specialised in
defending those accused of what he terms 'political violence'."
Mr Macdonald, who has practiced criminal law for 25 years, will take up the £145,000 post in autumn when the current director of public prosecutions, Sir David Calvert-Smith, retires.