Elton John has appeared as a witness as part of Kevin Spacey’s defense in the actor’s ongoing sex assault trial in London.

The Rocketman star — who recently gave his final concert — appeared Monday alongside his partner David Furnish via video link from his lawyer’s office in Monaco, becoming the most high-profile witnesses to be called so far in the trial.

John was asked about Spacey’s appearance at one of his White Tie and Tiara Balls, held annually to raise money for the musician’s AIDS foundation; he recalled that Spacey had flown in at the last minute to attend the event in 2017. According to the Evening Standard newspaper, John confirmed that Spacey had stayed the night at their home in Windsor following the ball, and that he and Furnish had stored a red Mini car that the actor had bought at the event’s charity auction (a car he had told jurors was “the most expensive Mini Cooper ever”).

Furnish asserted that, to his knowledge, Spacey had only ever been a guest at one of their balls, and, when asked by prosecutor Christine Agnew, stressed that there was no chance of Spacey’s attending another without having been photographed.

“It was understood we were promoting a charity involving the eradication of stigma surrounding disease,” he said. “For celebrities wanting to come to our event, it was always understood they needed to be photographed.”

Furnish added that Spacey’s surprise appearance in 2017 had created a “lot of buzz and excitement.”

John was also asked about a photo of him leaving London’s Victoria Palace theater after a performance of Billy Elliot, asserting that the photo showed him “looking straight forward at my car,” and that he didn’t notice anybody else. “Anyone who is on my periphery, I wouldn’t notice them. It could be the Queen, and I wouldn’t notice her,” he said.

Spacey is facing 12 charges, including four counts of indecent assault, seven counts of sexual assault, one count of causing a person to engage in sexual activity without consent, and one count of causing a person to engage in penetrative sexual activity without consent. He has pleaded not guilty to all 12, with his defense having labeled the case of the prosecution as “weak” and accusing the complainants of lying and overexaggerating their stories.