Crown Agent Norman McFadyen, who led the Crown's discredited investigation into the Lockerbie case, has been praised by Lord Advocate Elish Angiolini as he steps down to take up appointment as Sheriff.

MacFadyen, who was investigated by Lothian an Borders CID in 2009 when he was reported by MSP Christine Grahame over concerns about his handling of crucial evidence, was praised by Angiolini for his "great professionalism and integrity" in his handling of the case.

After three weeks investigation, no charges were brought against him.

Earlier this month the Crown Office also attacked the BBC over a Newsnight investigation which challenged the explosives evidence offered by the Crown at the Zeist trial of Abdelbaset Ali Mohmed Al Megrahi.

"Norman McFadyen is an outstanding lawyer with a long and very distinguished career with Scotland's prosecution service," Angiolini said.

"He has served in a variety of senior posts before his appointment as Crown Agent and Chief Executive. These included Regional Procurator Fiscal for Lothian and Borders and Deputy Crown Agent. He also led the investigation into the Lockerbie bombing with great professionalism and integrity.

"Norman McFadyen has been an immense support to successive Law Officers over the years and he has played a key role in the modernisation of the Crown Office and Procurator Fiscal Service."

McFadyen had overall responsibility for the preparations by the Procurator Fiscal Service for the trial and appeal of the two accused in the Lockerbie case.

The Scottish Government's announcement of the appointment, which contains a career biography of McFadyen since 1976, omits all reference to his role in the Lockerbie affair.