According to the Cape Times, Mandoza was with Mhinga at the hotel on Sunday before she died.
"I phoned Mandoza who told me he was sitting at the hotel lounge with Mhinga. She was complaining about issues with her boyfriend," Mandoza's manager Vaughn Eton said.
"Clearly, that was bringing her down, but she seemed to be fine."
Police Captain Schalk Bornman said the R&B singer had no marks on her body.
"She was discovered by a staff member at the hotel. There is no evidence of a struggle or forced entry," Bornman said.
Sapa reported that a note was found next to her body, but it is not clear what it said.
Mhinga, who won three SA Music Awards including two for Best R&B Album in 2001 ('TKO') and 2002 ('Eject Yo Ass'), leaves behind a young son.
Modimolle rape victim Ina Bonnette will attend the court case of her estranged husband Johan Kotze.
"First and probably the most important thing I want to say is I'm sorry to all of you..."
A man - who reports suggested was the owner of a Cape Town nightclub - has been found dead.
