Lea Michele has warned there is some "huge shocking stuff" coming up in Glee.

The actress is Rachel Berry in the high school singing television show, which is now in its third season.

The star doesn't want to give much away about what's in store for viewers as the series continues, but she has admitted some of the storylines are surprising.

"We have some big celebrities coming on the show," she said. "We have some shockers, some huge shocking stuff that when I read the script, I threw the script across the room, I called my cast members and I was like, Did you read the last page?' It's going to get really exciting."

Glee is renowned for featuring music by some of the most well-known artists in the world. The show has included covers of Lady Gaga tracks and songs by Madonna, and it's a tradition they are continuing with.

"We're on episode 10 of 22," Lea explained to Access Hollywood. "We really did take it back to basics, focusing on the main characters. It's going to amp up again. We're going back now to - I know we're doing a theme episode of probably the most famous artist in the entire world. We're doing an episode of their music.

"We've done two of their songs before. Now we're doing a whole episode of their stuff."

Ricky Martin is due to appear in an upcoming episode of Glee, with Olivia Newton-John, Gwyneth Paltrow and Britney Spears having previously featured. Lea added fans can expect more cameos in the future.

"I have heard the rumours about Ricky and Gloria Estefan. Ryan [Murphy, Glee co-creator] told me that we have four major stars coming onto the show," she added.