TMZ has obtained photos ... showing the damage Michael Lohan allegedly caused to his ex-girlfriend's body during a domestic violence incident early Tuesday morning.
The pictures show bruising on Kate Major's upper right arm ... where she claims Lohan violently grabbed her during an argument in her Tampa apartment.
Major also has black and blue marks on her leg, which she claims she suffered when Lohan was shoving her around.
As we previously reported, Major told Tampa police ... Michael got violent and threatened to kill her after she refused to perform oral sex on him in her apartment.
Lohan was arrested and charged with domestic violence ... though he told police he never laid a hand on Major and "would never hurt her."
Michael is still in custody -- but he's set to face a judge this morning in the hopes of being released from jail.