The singer has been on a three-week break from her Prismatic world tour, enjoying the exotic Morrocan city of Marrakech.

A Morrocan holiday wasn't quite enough to celebrate her birthday, apparently, so New York Daily News reported she decided to fly 70 friends to Europe on short notice for a low-key celebration.

The Roar singer had initially planned to celebrate her birthday in Egypt, but cancelled plans once the media found out.

Instead, she flew all her nearest and dearest - including boyfriend Diplo - to Paris to party in private.

"They piled off the flight, her friends, assistants, her whole camp," a source told the Daily News. "She flew all of her friends out, all on her dime. DJ Mia Moretti was in the group, and Katy's boyfriend, Diplo."

While her birthday was on Saturday, the troop arrived in Paris-Le Bourget Airport on Sunday evening. The source said Perry looked relaxed on arrival in Paris, dressed in a black Adidas tracksuit with matching sliders and taking selfies with her boyfriend.

Later that evening Perry went to Michelin-starred restaurant Le Jules Verne, on the second floor of the Eiffel tower, with boyfriend Diplo and about 20 other close friends.

"She was all dolled up," said the source. "Her reservation was at 9:30pm, she left close to midnight."

In a whirlwind trip, the entourage left Paris the next day.

Diplo, real name is Wesley Pentz, is set to perform a DJ set in California on Wednesday, before performing a Halloween bash in Las Vegas.

The DJ was also expecting to become a father again soon, after the New York Daily News revealed his ex Kathryn Lockhart was pregnant with their second child.

"She's due in the next couple of weeks. Her friends recently had a baby shower for her," a source told the newspaper.

Diplo and Lockhart have a four-year-old son together, named Lockett. "She and Wes aren't together, but he's actively involved in [Lockett's] life."

Lockhart would have been pregnant at the time Perry was rumoured to have started dating Diplo in April this year, at Coachella.The Daily Mail reports Perry is keen to keep her relationship under wraps, and is happy now she feels in control of their romance.

"She's keeping this one undercover because she's learned her lesson. She's in control, but he likes that," said a source for the MailOnline.

"He knows she's in charge and respects her. She keeps tabs on him ... but she trusts him and that's the most important thing to her."

The couple reportedly split in May, but after getting their relationship back on track they've become more serious. The MailOnline's source says Perry has introduced him to her family, and everyone seems to get along well.

"Her family likes him a lot. You can see how comfortable she feels with him already because the whole crew hangs with him already and they approve," said the source.

"It's important that everyone gets along with him because [it] makes her crazy life easier."