American pop star Katy Perry has again sparked rumours that she is back with musician John Mayer after they were reportedly spotted enjoying a night out at the Chateau Marmont in Los Angeles.

According to Gossip Cop, the two were "part of a larger group" and "sat separately."

This comes after reports emerged that Mayer was at the Firework singer's party, to celebrate America's Memorial Day.

"They are just hanging out," an insider told E Online, "They are not putting a label on it."

The Teenage Dream singer has also been linked with Twilight heartthrob couple Robert Pattinson and Kristen Stewart's split. According to Hollywood Life, Stewart told Perry "to back off" from Pattinson and is upset that they have been spending so much time together.

Pattinson and Perry were spotted watching a wedding rehearsal at San Ysidro Ranch in Santa Barbara, California. The 27-year-old London-born actor was spotted in New York City with the 28-year-old Perry two weeks before he broke up with Stewart.

"[Kristen] feels hurt," the insider said, "She feels betrayed."

"The timing was never right [for Rob and Katy]," a source said, "Katy's the kind of girl who goes after what she wants until she gets it."

Russell Brand Opens Up about His Short-Lived Marriage to Katy Perry

The Forgetting Sarah Marshall star said that he never cheated on Perry as he covers July issue of Esquire magazine.

"I tried it and I loved it. I really think she's a lovely beautiful person [Katy Perry]," he said, "It's just hard isn't it? She's got a lot of options, I've got a lot of options, so you've got to really, really want it.

"Some of it's the fame, but I think getting married is… you've got a whole other person that you've got to make as important as you!"