Oppenheimer has swept the Baftas, where it was was named best film and won best director, best actor and best supporting actor.

Christopher Nolan’s epic biopic about J Robert Oppenheimer, the theoretical physicist described as the father of the atomic bomb, scored seven awards at the ceremony at the Royal Festival Hall in London.

The British filmmaker won his first Baftas following previous nominations for Inception and Dunkirk – and joked that his brother Jonathan, the co-creator of TV series Westworld, “beat him up here” by being in a chorus of a production 40 years ago.

He paid tribute to his star Cillian Murphy and added to those who backed the film: “Thank you for taking on something dark.”

The director also acknowledged the efforts of nuclear disarmament organisations to bring peace.

He said: “I do just want to say that our film ends on what I think is a dramatically necessary note of despair.

“But in the real world, there are all kinds of individuals and organisations who have fought long and hard to reduce the number of nuclear weapons in the world.

“In accepting this, I do just want to acknowledge their efforts and point out that they show the necessity and the potential of efforts for peace.”

Murphy was named best actor for the titular role and told Nolan: “Thank for always pushing me and demanding excellence because that is what you deliver time and time again.”

He said Oppenheimer was a “colossally knotty character”, adding: “We have a space to debate and interrogate and investigate that complexity and it’s a privilege to be a part of this community with you all.”

Robert Downey Jr won the best supporting actor prize for his role as Lewis Strauss, head of the Atomic Energy Commission and said of Nolan: “Recently that dude suggested I attempt an understated approach as a last ditch effort to resurrect my dwindling credibility.”

He said he owes the award to Nolan, producer Emma Thomas and Murphy, as well as “British influence”.

Oppenheimer also won the Baftas for best cinematography, score and editing.

Emma Stone was named best actress for Poor Things, the steampunk fairytale adaptation of the novel of the same name by Scottish author Alasdair Gray.

She paid tribute to writer Tony McNamara for coming up with the line “I must go punch that baby” in a memorable dinner scene, and also thanked her British dialect coach for “not laughing” when she said water in an American accent.

Poor Things won five prizes in total, including costume design, make up and hair, production design and visual effects.

Da’Vine Joy Randolph won the supporting actress prize for her turn as a grieving cook in The Holdovers, about a teacher forced to stay at school over the holidays, and hailed her character who would “never (have) got a chance to wear and a beautiful gown” and it was a “responsibility I don’t take lightly”.

Courtroom drama Anatomy Of A Fall won the first award of the night when it scored the prize for original screenplay.

The adapted screenplay prize was given to American Fiction, about a frustrated novelist who writes a book that propels him into the centre of the hypocrisy he disdains.

Writer Cord Jefferson said in a “risk-averse industry”, he was grateful his film was made.

Holocaust drama The Zone Of Interest, directed by British filmmaker Jonathan Glazer was named best film not in the English language and outstanding British film. It also won best sound.

The Boy And The Heron was named best animated film – while 20 Days In Mariupol was named best documentary.

MiaMcKenna Bruce won the EE rising star prize, the only film Bafta for by the public.

The star of coming-of-age film How To Have Sex appeared emotional on stage as she thanked her family and her “beautiful baby boy”.

The 26-year-old joked that she hopes her little sisters, who do not think “I’m cool”, will change their mind after her win.

The Bafta Fellowship, the highest honour of the British film academy, was presented to actress Samantha Morton, who was taken into care as a baby and spent time in and out of care and foster homes growing up.

She was visibly emotional as she collected her prize, which she dedicated to children in care, adding: “Film changed my life, it transformed me and it led me here today.”