It's alleged the peer took drugs with prostitutes and he is now stepping down from the House of Lords.
Yesterday, Lord Sewel apologised for the pain and embarrassment he has caused, after footage was released by the Sun on Sunday.
Writing in the Letters pages of The Times on Wednesday, Revd John Cameron of St Andrews said: "We all make mistakes and we all pay a price and that price can be out of all proportion with the mistake."
Revd Cameron also praised the 69-year-old former Chairman of Parliament's Privileges and Conduct Committee's career, saying John Sewel was a "very fine academic who rose from being a lowly research fellow in 1969 to vice-principal of Aberdeen University and dean of the Faculty of Law in 1995".
He added: "He served the city for years in local government and did stellar work for the Scottish Constitutional Convention. As Tony Blair's parliamentary under-secretary of state at the Scottish Office he piloted the Scotland Act 1998 through parliament and helped draft plans for the Scottish parliament."
Revd Cameron finished by saying: "I should like to thank him for all he has done for Scotland and to express my sorrow that it has ended this way."