Chris Brown was allegedly dumped by Karrueche Tran because he had a secret visit from Rihanna.

The Don't Wake Me Up singer recently spent time in a Malibu rehabilitation centre, where he sought help for anger issues.

Sources claim that while 24-year-old Chris was completing his court ordered rehab, ex-girlfriend Rihanna flew in for a secret visit.

Rumours claimed that Rihanna stopped by in December but an insider says it was actually in January that the Diamonds star visited Chris, news that has reportedly not gone down well with Chris' most recent squeeze, Karrueche.

“With Chris in rehab, [he] and Karrueche spoke every day and she stood by his side. She took a vacation to Turks and Caicos and told friends the entire time that they were really good and happy together," a source divulged to the New York Daily News' Confidenti@l column.

"She trusts Chris, but when it comes to Rihanna, she has a zero-tolerance policy. Then she found out about the trip.”

Chris and 26-year-old Rihanna were one of the hottest couples in showbiz until the rapper assaulted the Bajan star in 2009.

He and Rihanna have reunited in the past but broke up for good last year. His relationship with Karrueche has also been complicated, and Rihanna was rumoured to be the cause of a previous split between the former couple.

Karrueche is said to despise Rihanna, and the rehab visit has supposedly proved to be the final straw for her.

She cemented her single status on Twitter last week when she told followers that she wasn't dating anyone.

"He finally admitted that Rihanna had come to see him. She put her foot down and cut him off completely,” the insider added.

“She just looked at an apartment in Tribeca to buy... She isn’t taking any of Chris’ calls and he keeps calling her.”