"I was coming out from Kingston Crown Court, with an assistant who happened to be white and I was approached by these plainclothes police officers who basically said that 'you fit the profile and description ... who just took place was involved in a robbery'.
"I was simply taken aback and startled," Wallace said.
"He said to me 'where were you?' and I said 'well I was at Kingston Crown Court.' 'What were you doing there?' and I said 'well if you look inside my bag you'll see why.' When he saw my robes he was totally astonished."
It isn't the first time the quizmaster has been stopped by police on "suspicion of robbery" because of racial profiling.
"I was just getting off the train at Watford Junction and again I was approached by these two plainclothes police officers.
Wallace spoke to Auckland students as part of his New Zealand tour last year. Photo / File
"I was a bit startled why they were coming up to me and again he said the same thing to me that 'you fit the profile of a person we want to talk to about a robbery'. I was totally startled and again I had to show them my wig and gown, and they weren't even apologetic in relation to their conduct and response."
Wallace has since vowed to support Black Lives Matter and aims to help young people who deal with racism on a day to day basis.
"What's happening in England has been happening far too long. The way in which young black boys in particular have been stopped and searched has been done so in a disrespectful fashion, and the way in which they've been treated is totally disregarded for their human rights.
"I say to young people, not anybody can be like me, in terms of the way in which you respond. I will say to young people if you are stopped and searched, you've got nothing to fear if you've done nothing wrong."
