Benedict Cumberbatch appears on-screen with his parents

Actor Benedict Cumberbatch was joined on-screen by his real life parents in a new episode of TV detective series 'Sherlock'.

The 37-year-old actor reprised his role as Sherlock Holmes for the latest installment in the popular show, which aired in the UK on New Year's Day.

It has emerged that his mother and father joined their son in the special episode, reported Daily Mirror.

Timothy Carlton and Wanda Ventham, who are both actors, played Holmes' parents.

"(I was) so proud of them. They're Equity (actors union) card-carrying members but you know it was nerve-wracking because they are actors as well and yet they were brilliant and they were fantastic," Cumberbatch said.