A “river” of chocolate flowed down a motorway in Arizona after a lorry spilled its cocoa cargo.

More than 40,000lbs of liquid chocolate cascaded on to Interstate 40, east of the town of Flagstaff, after the tanker overturned.

The sweet treat was being transported at a temperature of 120C, according to Arizona’s Department of Public Safety.

“There is a river of chocolate blocking/flowing in the westbound lanes,” it tweeted. “This will be a sweet cleanup!

The spillage occurred the lorry’s trailer became detached from the cab, causing it to roll over.

The gooey mess took about four hours to clean up, with authorities pumping the melted chocolate onto nearby land.

Last month a street in Germany was paved with chocolate after a technical glitch caused a delivery tank at artisan confectioners DreiMeister to overflow.

More than 25 firefighters were called on to deal with the sticky slab, using shovels to pry colossal chunks of chocolate off the street.

They also used hot water and blow torches to remove chocolate that had settled in cracks and gaps in the road, before power-hosing the remaining mess.