Boxing star "Sugar" Shane Mosley is being investigated for an alleged domestic violence incident after his girlfriend told police he roughed her up this weekend ... TMZ Sports has learned.
Law enforcement sources confirm cops were called to an L.A. home just after midnight on Sunday morning. When they arrived to the scene, 45-year-old Shane was not there.
The accuser told cops she and Shane had been arguing earlier in the night -- but things escalated and Shane pushed her.
The woman claimed she suffered minor injuries and complained of pain.