Famed actor Idris Elba has officially joined the cast of "Star Trek Beyond."  Watch the unconventional announcement inside...

We've heard rumblings about this in the past...and now it's official.  Luther star Idris Elba has officially joined the cast of Star Trek Beyond, and his arrival was announced in a non-conventional way.  Instead of a press release, we learned about his involvement through a promotional video for a charity contest the film's cast is throwing.

The promo video stars cast members Chris Pine, Zoe Saldana,  Karl Urban, Zachary Quinto, Simon Pegg, Anton Yelchin, and John Cho as they reveal they're auctioning off a chance to win a walk-on role in the film to support their "Star Trek: To Boldy Go" initiative. In addition to the grand prize, there's an opportunity for six additional winners to visit the set to meet the cast.  

Towards the end of the clip, Chris says, "Idris, glad you could join us," as Mr. Elba strolls onto the set.

And there you have it.....Idris is on board. So far, the powers that be are mum about Idris' character.  Check out the announcement and Mr. Elba's breakdance moves....