Pic: BBC

A man’s head breaks the surface of water as two sets of razor-sharp oar blades bear down, in video of the aquatic antics which marred today’s Thames boat race in London - in which Cambridge beat Oxford in the most controversial of circumstances.

The lone man ducks beneath the oar blades as the boats pass on either side of him – narrowly avoiding potentially serious injury.

But that might not have been the end of the danger for the man - a flotilla of around 20 vessels tracking the action close behind could have mown him down, but for the quick action of crews and officials.

The race between the two teams of rowers was plunged into chaos by the incident.

It brought the 158th annual boat race between the two English universities to a stop at around 2.25pm.

The man was plucked from the water by officials and arrested by police after the stunt - at the mid-point of the race at Chiswick.

Referee John Garrett halted proceedings for 30 minutes. When racing resumed, Oxford lost the narrow advantage which they had held prior to the delay - then saw their hopes dashed when a clash with Cambridge left them minus an oar.

A Metropolitan Police spokesman confirmed a man is being held in custody, this afternoon.

“Officers from the Metropolitan Police Service Marine Policing Unit attended and took the man back to the riverside where he was arrested for a section 5 public order offence.

“He has been taken into custody at a west London police station.”