A man has allegedly used a shotgun to try and rob a wrecking business in Adelaide’s southern suburbs.

Police say a man allegedly armed with a shotgun entered the Lonsdale business on O’Sullivan Beach Rd just before 10am and demanded cash.

They say the suspect fled empty handed and on foot.

The alleged suspect is described as Caucasian, about 183cm tall, 25-30 years of age, unshaven with a goatee beard, and had a tattoo on the side of his neck.

He was described as wearing blue and black shirt and jeans.