Floyd Mayweather Jr. was in a fit of jealousy over a basketball player when he allegedly attacked his baby mama, Josie Harris and threatened to kill the pair ... this according to the police report obtained by TMZ.
According to the report, Mayweather read text messages on Josie's phone ... which included messages from C.J. Watson (pictured below), who plays for the Chicago Bulls. According to the report, Mayweather screamed, "'Are you having sex with C.J.?' Harris replied, 'Yes, that is who I'm seeing now.'"
According to the report, the 10-year-old son of Mayweather and Harris told cops he "saw his dad was on his mother and was hitting and kicking her."
The police report says Harris was taken to Southern Hills Hospital and treated for "minor facial injuries and a sore left arm." Pictures of the injuries were taken.
The police report goes on to say while Harris was at the hospital Mayweather called Georgia Parker -- Harris' friend who lives in the house -- and told her to get out of the house.
As for why Mayweather was arrested for grand larceny Friday ... the police report says he left with her Apple iPhone 4 ... valued at $322.17.
As we first reported, Josie Harris called the police at around 5 AM Thursday from her home in Vegas -- and when cops arrived she told them the professional boxer had attacked her and threatened to kill her.