ACT Policing are asking for the public's help to identify an armed thief who threatened staff at a Higgins store on Monday.

A man armed with a knife entered Food Works at Higgins around 10.30am, where he threatened a staff member and demanded cash.

He left the store with a small sum of cash and was seen driving away in a white Toyota Corolla.

No staff were injured during the incident.

The man is described as Caucasian in appearance and approximately 190 cm tall, with short light brown hair and a moustache. He was wearing a light green high visibility shirt with dark pants.

ACT Policing said the offender's hair was ''unusually cut'' in a semi-mullet, with shaven sides.

Contact Crime Stoppers on 1800 333 000 or via the website at www.act.crimestoppers.com.au.