Bill Winter and Alex Winter on the premiere of the film Panama Papers doc in Belfast

The journey of actor and director Alex Winter has been interesting.

His career has brought him to paradise, to hell, to the future, to the past and now to Belfast.

The first part of this trip is probably about his best-known role as a lazy guy, Bill S Preston Esq, in the movies Bill and Ted.

The films followed two American high school students who went back in time and even went to the afterlife.

Featured alongside a young Keanu Reeves, the sequel to science fiction comedies of the early 1990s still has a huge cult.

Thirty years later, with his director's hat, Winter's documentary on one of the biggest financial scandals in the world occurs as part of the Docs Ireland festival in Belfast.

Behind the camera

The Panama Papers tell the behind-the-scenes story of the journalists who investigated the largest leak of documents in the history of one of the world's most secretive societies.

Eleven million documents were disclosed by the Panamanian law firm Mossack Fonseca. They revealed in detail the functioning of part of the offshore financial sector.

The obvious question is how to move from Bill, a time traveler, guitarist, savior of the universe, to making a documentary about a global financial scandal.

"I've always been a filmmaker in the soul.I was a child actor and I spent a good part of my childhood on Broadway, but even when I was shooting the movies Bill and Ted I also made video clips and short films, "Winter told BBC News NI.

"So playing and shooting movies have always been on my songs, and documentaries have played an important role in that."

• Q & A: Panama Papers
• Huge leak reveals tax havens of elites

Although Winter has had other high profile roles in movies such as Lost Boys, he has remained mostly behind the camera ever since.

He has directed documentaries on Napster's illegal music sharing website, as well as a film on the use of online Bitcoin e-money in the darker areas of the internet.

"I have made several documentaries about technology and the Internet and have considered the Panama Papers as a crime story of the 21st century centered on these themes," he said.

"It was the largest coordinated corruption scandal in history, the largest coordinated act of journalism in history, which took place in the greatest secrecy and at the risk of telling the story."

"Even though the story had broken out in 2016, it was such an archive that I knew there would be more revelations and twists for years.

"In this way, I knew it would not be just a retrospective story and could play the role of a political thriller, but I also wanted to emphasize the great importance and necessity of journalism in the modern era. "

Return to the character

Northern Ireland has been on the map as a prime location for high-end television and movie projects in recent years due to productions such as Game of Thrones from HBO.

But over the past five years, feature-length documentaries produced in Northern Ireland have also experienced explosive growth, and many of them have had theatrical release.

The organizers of the Docs Ireland festival say that local production companies have the opportunity to meet international donors and broadcasters.

Winter believes that obtaining funding can often be the hardest part of documentary.

"I was fortunate to have a lot of my documentaries backed by a big network or a big studio." Panamanian newspapers were mostly funded by a premium cable channel in the United States.

But getting something that's sold is a challenge and takes time, it's certainly not easy to sell at a studio either and documentaries can be just as hard to get financing for scripted movies. "

Winter will not participate in the premiere of his new documentary in Belfast on Sunday, as he is currently shooting Bill and Ted's third film alongside Keanu Reeves.

The announcement of a screenplay for a third film was revealed at the Cannes Film Festival last year.

Speaking on the phone from California, he said, "We are in pre-production and we started shooting in a few weeks, but it's great to be working with Keanu again.

"We've always been very close friends, he's like a brother to me, we enjoy playing these characters because even though we're not like these guys, we get married in real life the same way , Bill and Ted do. "

Winter is working on several other documentary projects, but he acknowledges that he will always be connected to the Bill and Ted movies.

The Panama Papers is screened at the Queens Film Theater on Sunday 16 June at 4pm (Paris time) as part of Docs Ireland by the Belfast Film Festival.