Crofter's Tavern in Mosgiel, the scene of an armed robbery on Wednesday night.

An armed robber dropped a large amount of cash as he fled an Otago pub.

Police were called to Crofter's Pub and Liquor Centre on the corner of Bush and Gordon roads, in Mosgiel, following reports of a robbery about 10.30pm on Wednesday.

Detective Sergeant Dave Nelson confirmed $13,000 was taken after a man presented a knife.

A large amount of the cash was left behind as he fled the scene.

The offender remained at large, but was described as being Maori, of solid build and about 1.8 metres tall.

Police were reviewing CCTV footage of the incident.

A spokesman for the pub declined to comment.