2:05 PM PT -- Brown just issued a statement adamantly DENYING the allegations he attacked Marzette-Sanders and vowing to clear his name.
"I am aware that my ex-girlfriend has filed a civil suit against me. I deny the claims," Brown said ... "They are false."
"I believe in the court system where I will clear my name. I will not be making any further comment at this time."
11:48 AM PT -- TMZ Sports contacted the Bastrop County Sheriff's Office and a spokesperson told us there is an active investigation into Brown.