In May 2012, after receiving an anonymous letter via a journalist, police investigated allegations that Hall had committed historical sexual offences against prepubescent and adolescent girls. He was charged with multiple sexual offences in December 2012 and January 2013. Although he initially denied any wrongdoing, he pleaded guilty in April 2013 to having indecently assaulted 13 girls, aged between 9 and 17 years old, between 1967 and 1986. When his guilty plea was made public in May 2013, the BBC terminated his contract and subsequently announced that it would launch an inquiry into his conduct at the corporation. On 17 June 2013, Hall was sentenced at Preston Crown Court to 15 months in prison. Following sentencing, the Attorney General's office received complaints that the sentence was unduly lenient. It was referred to the Court of Appeal for review and on 26 July his sentence was increased to 30 months. Further investigations took place and on 23 October 2013 the CPS announced that Hall was to be charged with a further 15 offences of rape and one of indecent assault upon two girls between 1976 and 1981.
In October 2013, it was announced that he would be stripped of his OBE after the award was formally "cancelled and annulled" by the Queen.
