Police are investigating an armed robbery where a man was allegedly threatened with a knife in Sydney’s west overnight.

About 8.50pm yesterday (Friday 26 April 2013), a man entered a convenience store on Bringelly Road, Kingswood, and allegedly demanded cash.

Investigations have revealed he was armed with a knife.

The man was handed an amount of cash before fleeing the store.

The 26-year-old male employee gave chase for a short distance before the man got into a car and was last seen travelling west on Orth Street.

St Marys Police attended and established a crime scene.

The man has been described as being of Caucasian appearance, 180cm tall, medium build and wearing a blue jumper and black shorts.