Police are calling on the public to help identify a man who stole a powered wheelchair from another man, leaving him stranded on a public toilet in Federation Square.

Key points: Suspect was last seen riding the chair towards Batman Avenue

Suspect was last seen riding the chair towards Batman Avenue Victim was left stuck in the toilet for about an hour after the theft

Victim was left stuck in the toilet for about an hour after the theft Offender was Caucasian in appearance and looked to be in his early 20s

The unknown man struck up a conversation with a 54-year-old St Albans man, who uses a wheelchair, at Flinders Street Railway Station at about 11:00am.

The pair then headed to a toilet in Birrarung Marr park, where the unidentified man helped him into the restroom.

He then took off in the wheelchair.

The man was described by police as being in his early 20s and Caucasian. ( Victoria Police )

The man was unable to move without the chair and was stuck in the toilet for an hour before a passer-by stopped to help.

Police say the offender was last seen travelling east in the wheelchair, heading towards Batman Avenue.

The wheelchair was found later at the corner of Wellington Parade and Jolimont Road in East Melbourne.

Police are yet to arrest the thief, who was wearing a Santa hat, camouflage pants, a black jumper and white sneakers.

Police described him as Caucasian in appearance and aged between 20 and 24-years-old.

The wheelchair is maroon with a dark canopy and several shopping bags tied to it.

Police have released images captured by CCTV cameras in the square in the hope that someone will recognise the suspect and help locate the chair.

Those with information that might assist police are urged to contact Crime Stoppers on 1800 333 000 or submit a confidential report online at www.crimestoppersvic.com.au.