John Travolta. (AP Files)

John Travolta and his wife Kelly Preston are gradually coming to terms with the tragic loss of their son Jett with the help of daily Scientology counselling sessions.

The grieving Hollywood stars lost their 16-year-old boy in January after he suffered a seizure during a family vacation in the Bahamas.

Travolta was forced to relive the horror of the incident as he gave evidence against paramedic Tarino Lightbourne, who treated Jett, and his lawyer Pleasant Bridgewater, a former Bahamas senator, during their extortion trial in October.

The case was declared a mistrial after Bahamian politician Picewell Forbes prematurely announced the verdict to the media before the jury had officially come to a decision.

The Travoltas returned to the spotlight last week as they went back to work to support their new release Old Dogs, opening up about their family tragedy for the first time in an interview with members of the U.S. press.

The Grease star admits their dedication to the controversial religion has played a big part in helping them overcome their grief, reports USA Today newspaper.

He says, "We've been working very hard every day as a family to heal. We have our own way of doing it, and it (Scientology) has been helping. You need your friends a lot in times like that."

Preston reveals they regularly attend counselling sessions and admits the show of support from friends and fans has been overwhelming: "(The) outpouring of love from, really, worldwide has been extraordinary. It's been our friends, our family, our church. We partake in spiritual counselling pretty much daily.

"It's a tricky thing. Sometimes, something that's right for the moment is not right the next day. Being with people who are important to you, being with people that you love, I think that's what has primarily helped us the most. Sometimes, being alone, too."

The couple felt it was time to return to work to promote Old Dogs because the stars wanted to celebrate their nine-year-old daughter Ella's acting debut in the movie.

Travolta adds, "We decided it was OK to come out and promote, to introduce her to the world and to give her a beautiful future in film."

A Bahamas judge has ordered a retrial in the extortion case, which is expected to take place next year.