TMZ has learned about a criminal investigation being conducted by the Los Angeles police department against R & B singer, Tyrese. He allegedly punched his pregnant girlfriend in the arm and thigh.

Sources say the couple got into a terrible arguement around 5:30am at their home in Los Angeles. Apparently, Tyrese hit his girlfriend who is 3 months pregnant with his chld. He then drove away and paramedics were called to the scene. No comment yet from Tyrese's reps.

Posted 3:30pm EST 01-04-2007