Undie thief frightens Vic women

Three women are having trouble sleeping at night after finding out a strange man has been performing lewd acts with their underwear outside their homes, police say.

A man aged 20 to 30 has been stealing knickers off apartment balconies in Richmond since December 26.

Detective Sergeant Bill Brown said the man had returned on five occasions since Boxing Day to raid the clothes horses of two apartments where three young women live, taking 21 pairs of bikini bottoms and knickers.

"Footage shows the male ... going through women's clothing ... and handling female underwear as well," he told reporters on Tuesday.

"After that, he appears to masturbate and leaves the area shortly after that."

Victim Jessica, who did not use her real name, said she realised someone had interfered with her underwear when she noticed her clothes had been re-pegged.

The second time it happened she called the police and installed a camera to catch the man, who also stole knickers.

"It starts to make you wonder if someone is watching your house and potentiality stalking you," she said on Tuesday, visibly upset.

The man would come back even when all housemates were at home and the lights had been left on, Jessica said.

The footage captured on January 24 and January 30 shows what police believe is the same man, based on his distinctive clothing.

Jessica said she felt sick when she viewed the most recent footage.

"I felt bile rise in my throat seeing what he was doing to our underwear while we were sleeping in our beds 20 metres away," she said.

Det Sgt Brown said the man might be entering the apartment block on Lennox Street, Richmond, via the fence or a back gate.