Police are investigating an armed robbery of a home improvement store in Rouse Hill today.

About 11.30am (Monday 18 January 2016), a man entered the store on Commercial Road and removed a knife and two power tools before attempting to leave the premises without paying for the items.

Police have been told when a staff member attempted to stop the man; he produced a second knife from his pocket and threatened the employee, and several others who also attempted to stop him from leaving.

The armed man left the scene with the items in a Nissan Pulsar, with two other people in the vehicle.

Officers attached to The Hills Local Area Command were contacted and commenced investigations.

As inquiries continue, police would like to speak to a man who may be able to assist with them.

He is described as being of Caucasian appearance, about 20-25-years-old, of slim build, and with short sandy-coloured hair.

The man was seen wearing a light blue, black and white t-shirt, short black shorts, and grey running shoes.