Police in the US are investigating the fatal shooting of a YouTuber while filming a robbery prank on strangers last Friday.

Timothy Wilks, 20, was filming a prank video with a friend when they approached a group of people while holding butcher knives.

David Starnes Jr, 23, was with the group of people and unaware the pair were playing a prank, shot Wilks in self-defence, WSMV News reports.

The shooting took place in the parking lot of Urban Air, a trampoline and adventure park in a strip mall in Nashville, Tennessee.

Police said in a statement Starnes admitted to shooting Wilks at the scene.

Starnes was legally permitted to carry a handgun, according to Tennessee law.

Police said Wilks' friend told them that they were participating in a "prank" robbery as part of a YouTube video.

According to Metropolitan Nashville Police Department, no charges have been placed and the investigation is still ongoing.