Mariah Carey 'Had to Leave' James Packer Because He Was 'Not Mentally Healthy' - But His Side Claims She 'Has Issues': Sources

New details about Mariah Carey‘s split from fiancé James Packer are making one thing clear: there appears to be two sides to the breakup.

A source close to Carey previously told PEOPLE that “James has not been in a mentally healthy place and has not been present for Mariah or her family.”

They add, “His behavior was not a desirable situation for Mariah so she unfortunately had to leave him.”

A rep for Carey, 46, confirmed the pair are on the rocks after their Greece vacation took a turn for the worse last month. “Mariah and James had a fight in Greece, and have not seen each other since. The fight was not because of any cheating allegations or excessive spending by Mariah,” the rep said in a statement to Entertainment Tonight.

However, Packer’s rep told PEOPLE claims he’s mentally unstable are “simply not true.” According to a source close to the billionaire businessman, it’s “typical Mariah to just twist things that don’t sound good to her. They split because she has issues.”

“James is definitely an oddball, but a brilliant great guy. Mariah has had mental breakdowns in the past. She hasn’t been acting very mentally stable lately. To put her issues on James is ridiculous,” the Packer source told PEOPLE. The source also insists the Australian mogul and Carey “definitely won’t be getting back together now.”

The Carey source tells PEOPLE that the claims against Mariah being mentally unwell are “comical,” arguing that “she’s having the most productive year” with her Vegas residency, upcoming E! show and tour dates.

Packer, 49, proposed to Carey with a 35-carat diamond engagement ring in January. They were linked as a couple after being photographed getting cozy while on an Italian vacation in June 2015. Months later in September, they made their red carpet debut at The Intern premiere in New York City.

Carey was previously married to Nick Cannon from 2008 – 2015, and the former couple are parents to 5½-year-old twins Monroe and Morocco. Before Cannon, she was married to music executive Tommy Mottola.

Packer has three children with his ex-wife Erica Baxter.