The race was staged on the eastbound carriageway of the dualled A14 near Huntingdon in Cambridgeshire.

A Cambridgeshire police spokeswoman said officers were alerted by the neighbouring Suffolk force.

Police had spotted a large convoy of vehicles travelling towards Cambridgeshire at around 0830 GMT on Sunday.

Around 200 people watched the race

They dispersed but half an hour later converged on the A14 at Huntingdon.

Some of the vehicles set up a slow-moving roadblock to allow the two competitors to race along the dual carriageway.

An estimated 200 people watched the race with large sums wagered on the outcome.

"This was stupid and irresponsible behaviour which put other road users at risk," said the spokeswoman.

Some congestion was caused, although queues were kept to a minimum because it was a Sunday morning with little heavy traffic.