Actor Vin Diesel struggled to control his emotions on camera when her returned to work on the new Fast & Furious film following Paul Walker's car crash death in November (13).

Production on the seventh instalment of the film franchise was put on hold to allow the cast and crew time to mourn the actor's death, and writers a chance to rework the movie's plot.

And Diesel explains that when he returned to shooting, the tragedy was still affecting his acting.

He says, "It's a heavy thing... I grew up in the (nightclub) bouncing world and we lost people bouncing, but the brotherhood in Paul Walker was something completely different.

"We grew up in the business together and we became famous together and we represented the biggest franchise together and he was my partner and it's a strange thing... I've been acting all my life and they don't teach you in acting how to mourn someone and simultaneously pretend they're in a scene with you. It's one of the darker moments in my journey...

The actor also explained that Walker's death made him rethink shooting dangerous action scenes in films.

He continues, "A lot of people don't realise when you do these action movies you put your life on the line more than you should... When you're doing these action films and you're... for lack of a better description, a method-like thespian, and when you go into these action sequences you put yourself in harm's way in kind of an unfair fashion..."

Fast & Furious 7 will hit theatres next April (15).