David Hasselhoff expresses dismay over man injured trying to stop theft of life-sized adverts

Hasselhoff tweeted about Tuesday's robbery in Shelton, urging people to pray that the 36-year-old clerk makes a full recovery

The former Baywatch and Knight Rider star appears in adverts for Cumberland Farms iced coffee and the signs have become popular items to steal, police have said. (AP)

The actor and singer David Hasselhoff has expressed dismay after learning that a shop assistant in the US was critically injured while trying to stop thieves from stealing adverts featuring life-size images of him.

The former Baywatch and Knight Rider star appears in adverts for Cumberland Farms iced coffee and the signs have become popular items to steal, police have said.

According to reports a 36-year-old clerk at a Cumberland Farms in Shelton, Connecticut, was badly injured after seeing a man put some of the signs, which feature Mr Hasselhoff on a surf board, into a four-by-four shortly after 1am on Tuesday.

Police said the driver of the car pulled up next to the life-size images, cut them off the light pole to which they were attached and placed them in the boot of the vehicle.

The shop assistant approached the vehicle in a bid to get the posters back, but was hit as the vehicle sped away.

Hasselhoff tweeted about Tuesday's robbery in Shelton, urging people to pray that the 36-year-old assistant makes a full recovery.

"I am shocked & truly saddened about the Cumberland farms store clerk tragedy," Hasselhoff said in a posting on his official Twitter account. "My heartfelt thoughts and prayers are with him and his family!"

The Cumberland Farms worker, whom authorities have not named, suffered a head injury when he was hit by the thieves' sport utility vehicle and dragged, police said.

He remained hospitalised in critical condition Wednesday.

A 19-year-old man came forward Tuesday evening and confessed that he was the driver of the four-by-four, Shelton police said on Wednesday.

Authorities have not released the man's name, but say he is cooperating. Police say two other people were involved in the theft. Lt. Robert Kozlowsky said police have recovered the two stolen signs.

Cumberland Farms sent several employees to Connecticut to offer any help they can to the shop assistant and his family, company spokeswoman Carin Warner said.

Warner said the number of thefts of the Hasselhoff signs has significantly decreased since last year.

Additional reporting by Associated Press