Meryl Streep, the star of The Laundromat, Steven Soderbergh’s irreverent comedy about Mossack Fonseca, the law firm that masterminded offshore tax schemes for some of the world’s most rich and powerful, has praised the reporters who uncovered the story.

In Soderbergh’s film, Streep plays a fictional Texan widow who digs into the fate of her late husband’s savings, ultimately exposing the company directors, Jürgen Mossack and Ramón Fonseca, played in the film by Gary Oldman and Antonio Banderas.

Speaking in Venice ahead of the film’s premiere on Sunday, Streep was eager to stress that the legwork was in fact done by about 300 international investigative reporters who broke the story in 2016.

The film, she said, “is an entertaining, flash, funny way of telling a very, very dark joke that’s being played on all of us. And many of the victims are journalists who got the word out.”

Quick guide 10 key films at the Venice film festival Show Hide The Truth

Venice’s opening night spot goes to the latest film by Hirokazu Kore-eda, whose Shoplifters won top prize at Cannes last year. Catherine Deneuve plays an ailing French star who returns home for a tricky reconciliation with daughter Juliette Binoche, accompanied by her husband (Ethan Hawke) and young child. Joker

Joaquin Phoenix is the cracked aspirant comedian in this drama from Todd Philips that’s reportedly 80% King of Comedy to 20% The Dark Knight. Robert De Niro co-stars in what could well be the first comic book movie to bag a best picture Oscar. Marriage Story

Noah Baumbach’s latest is the story of a cross-coastal divorce starring Adam Driver and Scarlett Johansson. Like his most recent film, The Meyerowitz Stories, this has been bankrolled by Netflix. Laura Dern, Alan Alda and Ray Liotta co-star as loved ones – and lawyers. The King

Man of the moment Timothée Chalamet is Henry V in this lush, tough Shakespeare adaptation from David Michôd. Ben Mendelsohn is Henry’s father; Robert Pattinson, Joel Edgerton and Chalamet’s girlfriend, Lily-Rose Depp, offer support. The Laundromat

Meryl Streep leads Steven Soderbergh’s fictionalised take on the Panama Papers leak. Streep and Soderbergh are sailing to Europe on the Queen Mary 2, shooting another feature en route. Seberg

Kristen Stewart plays Jean Seberg in this biopic focusing on the actor’s years as an FBI target on account of her support for the Black Panther party – taking a role which Stewart’s mentor, Jodie Foster, first considered playing in 1991. An Officer and a Spy

A controversial slice of history – the Dreyfus affair – is brought to the big screen by a controversial director: Roman Polanski. Starring Jean Dujardin, it is based on the book by Robert Harris. The Perfect Candidate

Saudi Arabian director Haifaa Al-Mansour – one of only two women with films in competition – returns after the success of 2012’s Wadjda with the tale of a young doctor who makes a bid for office in a municipal election. Ad Astra

Brad Pitt follows in the footsteps of Sandra Bullock, Ryan Gosling and Matt Damon by heading into space in search of awards. James Gray’s drama will be a major player at Venice; Liv Tyler, Tommy Lee Jones and Ruth Negga co-star. American Skin

Nate Parker’s slavery epic Birth of a Nation won raves in 2016 before allegations of sexual misconduct by Parker took the shine off considerably. His belated return is a revenge drama about a janitor whose son is killed by a police officer.

Streep singled out Daphne Caruana Galizia, the Maltese investigative reporter who was killed by a car bomb outside her home in 2017. “People died and people die still to get the word out. This movie is fun and it’s funny but it’s really, really, really important.”

Asked about her character’s motivation in her search for answers, Streep said: “Grief is a great motivator. The parents of the children shot at Parkland high school, the parents of the children shot at Newtown, Connecticut – those people don’t stop; they don’t stop in trying to change the world. If it’s personal, you don’t stop, and we rely on those people, for whom it really counts, to save us all.”

Streep and Soderbergh arrived in Europe a few days before the premiere on the Queen Mary 2, the ocean liner on which most of their next film, Let Them All Talk, was shot.

Citing Dr Strangelove – Kubrick’s satire about the nuclear arms race – as inspiration for The Laundromat’s tone, Soderbergh said he felt “a dark comedy would have the best possible chance of remaining in the minds of the viewers and also gave us the opportunity to use the complexity of these kind of financial activities almost as a joke, almost as a setup for a punchline. Otherwise viewers would feel as if they were being educated as opposed to entertained.”

The director praised the UK for recently enacting legislation – in the form of unexplained wealth orders – to identify and potentially investigate people purchasing UK assets with “extreme wealth that seems to have come from nowhere”.

“I think that’s a really interesting way to attack this. There’s no universe in which that legislation would be enacted in the US. Which begs the question: why would you be against this?”

Despite Streep being a vocal critic of Donald Trump, none of the panel named the current White House administration, but Soderbergh alluded to a heightened relationship between such financial scams and climate change. He then cited figures suggesting that about 50 of the world’s richest people now hold the same wealth as the poorest half of the world’s population. “That doesn’t seem to me to be a sustainable paradigm, and I think transparency is the only solution.”

“It’s a very troubling time,” he continued, “but speaking about it is the beginning. You can get people wondering on a day-to-day basis: how am I participating in this?”

Jake Bernstein, on whose nonfiction book Secrecy World the film is loosely based, exploded the common misapprehension that tax havens are “warm and sunny and have palm trees. One of the the biggest tax havens is the United States of America.”

Bernstein claimed that anonymous shell companies make over $1bn (£822m) a year in Delaware, monies which may be funding shady enterprises in other parts of the world. “It’s about raising awareness and having people demand better of their government and their public servants.”

Oldman said he hoped the film’s release model – its distributor is streaming giant Netflix – would aid its chances of having a real-world impact. “You’ve got something this serious and you wanna get that out to as many people. Can art bring about change? Yeah – if people see it. And this movie will reach a lot of people.”

Streep, fresh from success on the second season of HBO series Big Little Lies, reiterated her personal preference for cinema over TV. “I’d rather see it big. But the kids these days, they don’t care.”