The BAFTAs are reportedly taking Sunday’s prank and security breach “very seriously.”

Viewers were bewildered when Christopher Nolan and his wife, “Oppenheimer” producer Emma Thomas, took the stage to accept the award for Best Film — only for a complete stranger to join them.

“A social media prankster was removed by security last night after joining the winners of the final award on stage — we are taking this very seriously, and don’t wish to grant him any publicity by commenting further,” a BAFTA spokesperson told Variety on Monday.

The incident occurred at the very end of the night after Michael J. Fox presented the nominated films: “Killers of the Flower Moon,” “The Holdovers,” “Anatomy of a Fall,” “Poor Things” and “Oppenheimer.”

“Oppenheimer” had already won six awards at Britain’s equivalent of the Oscars when Fox announced it as the winner for Best Film. As Nolan, Thomas, Cillian Murphy and producer Charles Roven took the stage to accept the award, they were suddenly joined by an unidentified man dressed in a black suit and tie.

Nobody on stage, including Fox and BAFTA host David Tennant, inquired why he was there. The interloper made his way on stage when Thomas urged the rest of her colleagues to join her.

The prankster casually walked off stage with the “Oppenheimer” group when the ceremony concluded, but appeared to tuck something under his arm before security apprehended him. According to The Guardian, the man is a YouTube personality who has a history of sneaking into awards ceremonies.

“Oppenheimer” swept most categories it was nominated in, including the Best Leading Actor prize for Murphy, who portrayed the titular physicist, and the Best Supporting Actor prize for Robert Downey Jr., who portrayed Atomic Energy Commission head Lewis Strauss. Downey Jr., Murphy and Nolan are all nominated for this year’s Oscars.

The 96th Academy Awards air March 10 on ABC.