Image copyright Getty Images Image caption The characters Bill & Ted played by Alex Winter and Keanu Reeves

It's been an interesting journey for actor and director Alex Winter.

His career has taken him to heaven, hell, the future, the past, and now Belfast.

The first part of this journey relates to probably his most well known role as the time travelling slacker, Bill S Preston Esq, in the Bill and Ted Movies.

The films followed two American high school students while they travelled back in time and even took a trip to the afterlife.

Starring alongside a young Keanu Reeves, the science fiction comedy sequels from the early 1990s still have a huge cult following.

But 30 years later, with his directing hat on, Winter's documentary on one of the world's biggest financial scandals is playing as part of the Docs Ireland Festival in Belfast.

Behind the camera

The Panama Papers tells the behind the scenes story of the journalists who investigated the biggest documents leak in history from one of the world's most secretive companies.

Eleven million documents were leaked from the Panamanian law firm Mossack Fonseca. They revealed in detail how parts of the offshore financial industry worked.

Image copyright Alamy Image caption Alex Winter as Bill (left) and in 2015

The obvious question is how you go from playing Bill, a time-travelling, guitar-playing, saviour of the universe, to directing a documentary about a global financial scandal.

"I've always been a film-maker at heart. I was a child actor and spent a good deal of my childhood on Broadway, but even when I was doing the Bill and Ted movies I was also directing music videos and short films," Winter told BBC News NI.

"So acting and film-making have always run on both tracks for me, and documentary films have been a big part of that."

Even though Winter had other high profile acting roles in movies such as Lost Boys, he's mostly stayed behind the camera since then.

He has directed documentaries on the illegal music sharing website Napster, as well as a film looking at how the online electronic cash currency Bitcoin is being used in the darker parts of the internet.

"I've made several documentaries that deal with technology and the internet and I saw the Panama Papers really as a 21st century crime story, with these themes at the centre of it," he said.

"It was the largest co-ordinated corruption scandal in history that took the largest co-ordinated act of journalism in history, working in complete secrecy and at great risk to tell the story."

Image caption A scene from The Panama Papers, which documents how a team of reporters exposed large scale off-shore tax evasion

"Even though the story had broken in 2016, it was such a vast archive I knew there would be more revelations and twist and turns for years.

"In that way I knew it wouldn't just be a retrospective story and could play like a political thriller, but I also wanted to highlight the great importance and the need for journalism in the modern era."

Getting back into character

Northern Ireland has been put on the map as a prime location for high-end TV and film projects in recent years because of productions like HBO's Game of Thrones.

But the last five years has also seen a surge in feature-length documentaries produced in Northern Ireland, with many securing theatrical releases.

Organisers of the Docs Ireland Festival say it's an opportunity for local production companies to meet international funders and broadcasters.

Winter believes securing funding can often be the hardest part of making a documentary.

"I've been lucky enough to have many of my documentaries backed by a big network or studio, the panama papers was primarily financed by a premium cable channel in the US.

But getting anything sold is challenging and takes time, its certainly not easy to sell to a studio either and the documentaries can be just as difficult to secure funding for as scripted films are."

Winter won't be at the Belfast premiere of his new documentary on Sunday because he is currently filming the third Bill and Ted movie alongside Keanu Reeves.

News that a script had been written for a third film was revealed at the Cannes film festival last year.

Speaking on the phone from California he said: "We're in pre-production and we start shooting in a couple of weeks but it's great working with Keanu again.

"We've been super-close friends all along, he's like a brother to me. We're enjoying playing these characters because even though we're nothing like these guys, we riff of each other in real life in the same way Bill and Ted do."

Winter has a number of other documentary projects in the works, but he acknowledges that he'll always be connected to the Bill and Ted movies.

The Panama Papers is screening at Queens Film Theatre at 16:00 BST on Sunday 16 June as part of Docs Ireland by the Belfast Film Festival.