John Travolta thanks co-stars for helping him grieve the death of his son

John Travolta has thanked his co-stars for helping him grieve the death of his son.

The 55-year-old actor has not taken part in any promotion for new movie 'The Taking of Pelham 1 2 3' as he attempts to get over the loss of 16-year-old Jett, who died following a seizure in January.

In a letter posted on his website, John wrote: "Director Tony Scott, Denzel Washington, Luis Guzman, John Turturro, James Gandolfini and Sony Pictures stepped up without hesitation to help promote this wonderful film, and their unselfish efforts have allowed my family the additional time to reconcile our loss.

"I am very proud of the efforts we have all made in making this movie, and I want each and every one of you to enjoy it. I promise you, you won't be disappointed."

John – who plays one of a team of men who take a train hostage in the film – added he was delighted with the "freedom" he was given in the movie.

He said: "I was allowed to define, and then become, the ultimate evil mastermind. This role as an actor gave me the chance to dispense with all moral and ethical limitations and explore just how bad this character could really be."

Last week, Denzel revealed John and his wife Kelly Preston were finally coming to terms with their grief.

He said: "It's a process. He is trying to work it out, it's a tough situation. He is a wonderful actor and an even better human being. We talked a couple weeks ago for a long time and he is doing as well as can be expected."