New South Wales Police have asked for public assistance after a man in a wheelchair was allegedly robbed just outside a Sydney train station after agreeing to let a stranger use his phone.

Police say a man in a wheelchair got off the train at Guildford, in Western Sydney, at around 9.30pm on Wednesday September 7. While exiting the train station, he was assisted getting up a ramp by a passerby.

Image of the man police say may be able to assist with inquiries. Credit:NSW Police

Police allege the stranger then asked the man if he could use his mobile phone. Once it was handed over, the stranger took it and ran off.

Police have released images from CCTV footage of a man they say may be able to help them with their inquiries, who is described as Caucasian, between 170cm and 180cm tall, aged in his late 20s or early 30s and was wearing a baseball cap and a Chicago 23 basketball jersey.

Fairfax Media