Gary Oldman secretly cast by Christopher Nolan in cameo role

They were exploding with glee.

“Oppenheimer” fans were delighted to discover director Christopher Nolan had secretly cast veteran actor Gary Oldman in the 2023 biopic, Entertainment Weekly reported.

Oldman, 65, previously appeared in the Nolan-helmed “Dark Knight” trilogy. He is also known for his Oscar-winning portrayal of Winston Churchill in the 2017 film “Darkest Hour” and Sirius Black in the “Harry Potter” films.

The Englishman’s presence in the hotly anticipated summer blockbuster was kept under wraps — Oldman did not walk the film’s red carpet when it premiered on July 11. His castmates notably left the screening to go on strike.

In the film, which tells the story of J. Robert Oppenheimer and the development of the atomic bomb, Oldman appears as a jubilant President Harry S. Truman, congratulating a guilt-ridden Oppenheimer (Cillian Murphy) on his achievement of building weapons of mass destruction.

The scene continues with Oppenheimer expressing that he has “blood on his hands,” a comment that reportedly angered Truman during the real-life meeting following the annihilation of Hiroshima and Nagasaki.

Prior to the release of the film, Murphy, 47, confirmed that the “State of Grace” actor would be a part of the film but did not specify the role Nolan, 52, had asked him to play.

“For me, every day, I was working with the best actors in the world, every single day,” said Murphy during EW’s “Around the Table.”

“You’d look at the call sheet and there’d be, like, Gary Oldman one day, and then Ken Branagh, and then these guys,” said the actor gesturing to co-stars Emily Blunt, Matt Damon and Robert Downey Jr. “It was very hard to be cynical when you’re working with that level of talent.”

The commercially successful flick, which The Post’s Johnny Oleksinski called a “masterpiece,” has stirred up some controversy.

In a notable departure for the typically chaste Nolan, “Oppenheimer” has been getting buzz — both good and bad — for including sex scenes.

According to the director, it was impossible to tell the story without sex.

“When you look at Oppenheimer’s life and you look at his story, that aspect of his life, the aspect of his sexuality, his way with women, the charm that he exuded, it’s an essential part of his story,” said Nolan of the eyebrow-raising scenes between the titular character and Florence Pugh’s Jean Tatlock.

“It felt very important to understand their relationship and to really see inside it and understand what made it tick without being coy or allusive about it — but to try to be intimate, to try and be in there with him and fully understand the relationship that was so important to him.”

One steamy moment was even called out as “a scathing attack on Hinduism” by India’s government.

The scene in question shows Oppenheimer and Tatlock engaged in sexual intercourse when Tatlock asks him to read a passage from the “Bhagavad Gita” while they continue to have sex.

An Indian official later slammed the scene in a tweet.

“It has come to our notice that the movie ‘Oppenheimer’ contains a scene which makes a scathing attack on Hinduism,” tweeted Uday Mahurkar, an information commissioner for the Indian government, to Nolan.

“As per social media reports, a scene in the movie shows a woman [making] a man read ‘Bhagwad Geeta’ aloud while getting over him and doing sexual intercourse.

“She is holding Bhagwad Geeta in one hand, and the other hand seems to be adjusting the position of their reproductive organs,” Mahurkar’s tweet continues. “The Bhagwad Geeta is one of the most revered scriptures of Hinduism. Geeta has been the inspiration for countless sanyasis, brahmacharis and legends who live a life of self-control and perform selfless noble deeds.”

Mahurkar calls the scene “a direct assault on religious beliefs of a billion tolerant Hindus.”

The official then asked if Nolan would “remove this scene from your film across the world,” adding: “Should you choose to ignore this appeal it would be deemed as a deliberate assault on Indian civilization.”