Good Samaritan beaten in Melbourne CBD

Detectives have released footage of a man in connection with the bashing of a good Samaritan who went to the aid of three women being abused on a busy Melbourne street.

The 43-year-old Ringwood man approached to help the women at the corner of A'Beckett and Swanston streets in the CBD about 7.30pm on May 5 and for his trouble was repeatedly punched in the face and head and left with grazes and bruising.

Investigators have released CCTV footage of a shirtless man walking along the street prior to the assault who they wish to speak to.