A VIDEO has emerged of a naked man's rampage through Dandenong's main business strip.

The bearded man terrorised lunchtime shoppers last Friday week as he made his way from Dandenong train station into town.

The Herald Sun has obtained footage of police and Protective Services Officers attempting to subdue the man with pepper spray and batons as he reaches the intersection of Foster and Lonsdale streets.

Steve Rawson witnessed the drama. "He's punched out these people at the traffic lights and then continued on punching people in the face until the cops arrived," he said. Mr Rawson said the man appeared to be impervious to pain.

"It was incredible. This bloke just wouldn't go down. They emptied cans of pepper spray into his face and it was just foaming on his face and he just did not feel it. He just kept walking," he said.

The footage shows shoppers calling 000 as the man punches a passer-by.

Moments later he is seen lashing out at a police officer, who douses him with pepper spray to no effect.

The man is also struck by police with a baton repeatedly before he succumbs.

A 43-year-old man was treated for capsicum spray exposure before being taken to Dandenong Hospital for assessment.

Police Association secretary Sen-Sgt Greg Davies said the video showed the dangers of police work and that pepper spray was not always effective.

"It just shows the problems of our mental health system and the fact that it almost inevitably ends up with the police who have to deal with it," he said.

Originally published as Naked man's run-in with law