Cribbens starred as Wilfred Mott in 'Voyage of the Damned' in 2007 and reappeared several times before having a key role in the fate of the Tenth Doctor in 'The End Of Time'.
Agutter told DS: "I've always enjoyed Doctor Who, yes. It's one of the few things we were allowed to watch on television in boarding school!
"I think Bernard's great. He himself said that he had the best time making it. He said it was really, really fun. He's always so good and whatever he creates is really interesting."
Of her own appearance in Doctor Who audio drama 'The Bride of Peladon', she added: "That was great. I suppose I can consider myself part of the Doctor Who family! It was lovely.
"It's a different thing. I'd love to film it, but there's something about standing in your boxes and just doing voices and creating this wonderful drama, and remembering how many years that's gone on. It's amazing, isn't it?"
A digitally restored print of The Railway Children is available on Blu-ray and DVD from May 3.