The showrunner recently announced that the show will dedicate an episode to Spears songs but he has now clarified that the singer will not be making a cameo.
"We're doing an episode about Britney Spears, but she's not on the show," he told E! Online. "It's not like anything we've ever done. There's a twist on it."
Murphy also admitted that many of the rumours about guest stars are "not true" but revealed that Kristin Chenoweth is "definitely coming back". He added that he is hoping to find roles for Javier Bardem and Jennifer Lopez, who has previously claimed that she would love a guest spot on the show.
"I love Jennifer," he said. "We keep talking about it. Again, we're just trying to find the right part."
However, Murphy dismissed speculation that Justin Timberlake will have a cameo, saying: "I don't know where that came from. We love him. He's the kids' favourite. A lot of this stuff comes from, 'Who would you like to be on the show?' And one of the kids said Justin and I said, 'Yeah, I love Justin'."
Murphy added that Jonathan Groff is unlikely to reprise his role as Jesse.
"He is doing a play in London til January," he explained. "We always have a soft spot for Jon, but he's not in the country."
Glee returns for its second season on September 21 on Fox.