British police are hunting a grinning thug who held a knife to a terrified shop worker's throat during an armed robbery, Sky News reported.

Security cameras caught Richard Halford, 19, being held in a headlock as the thug hissed: "Move and I'll slice you."

The robber even smirked at the security cameras as his accomplice stole cash and scratch cards from the Co-op store in Bury, Greater Manchester.

"One of them grabbed me from behind and I felt something sharp across my neck. My legs went weak," Halford told The Sun.

"I had my back to the door and all I heard was it slamming open. The next we knew, two guys came barging in asking us to take the tills off."

He added: "It was unbelievably scary. If he slipped I could have been a goner.

"I jump every time I hear a door open now."

Five terrified customers, including some young children, were in the store when the raid took place on Monday, November 30.

Click here for more and to see the video from Sky News.