Looks like the already-sizable "Avengers: Age of Ultron" cast may be even bigger than previously thought: In an interview published Sunday by London-based Telegraph, actor Idris Elba said not only does he reprise his role as Asgardian sentry Heimdall in the 2015 sequel, but Tom Hiddleston also will appear as fan-favorite trickster god Loki. Neither had previously been announced as involved in the film -- in fact, Hiddleston ruled out an "Age of Ultron" role last year.

In the interview -- focused on Elba's DJ stint at a hotel in Ibiza -- the "Luther" star describes a recently shot scene between he, Hiddleston and Chris Hemsworth, who plays Avengers mainstay Thor. "I'm in Avengers," the actor is quoted. "And I'm doing a scene with Chris Hemsworth and Tom Hiddleston, and they're like, [whispers] - 'Aren't you [meant to be] in Ibiza?'" The writer of the article, Craig McLean, noted that Elba was "not meant to talk about this," yet he "clearly enjoys doing things he's not meant to do."

The nature of the scene, and the size of Elba and Hiddleston's roles in the film, remains unrevealed, including whether or not Heimdall and Loki appear in the main action of "Age of Ultron," or in a flashback or dream sequence. Cameos from major Marvel Studios players have become fairly common, including Mark Ruffalo appearing as Bruce Banner in the "Iron Man 3" post-credits scene and Chris Evans playing Captain America -- well, Loki pretending to be Captain America -- in last year's "Thor: The Dark World."

Further in the interview, Elba discussed the abrupt transition from playing legendary revolutionary Nelson Mandela in "Mandela: Long Walk to Freedom" and doing reshoots for "The Dark World."

"I'd just done eight months in South Africa," Elba said of the "Long Walk to Freedom" production. "I came to England and the day I came back I had to do reshoots on 'Thor 2.' I was like, 'This is torture, man. I don't want to do this.' My agent said: 'You have to, it's part of the deal.' I'm actually falling down from a spaceship, so they had to put me in harness in this green-screen studio. And in between takes I was stuck there, fake hair stuck on to my head with glue, this fucking helmet, while they reset. And I'm thinking: '24 hours ago, I was Mandela.'"

"Avengers: Age of Ultron," written and directed by Joss Whedon, is scheduled for release on May 1, 2015.