A university professor was prevented from taking to hospital a student who suffered serious head injuries at last night's tuition fees protest.

The Independent Police Complaints Commission has begun an independent investigation into an allegation the 20-year-old was hit by a poice truncheon.

Peter Hallward, a Kingston University philosophy lecturer, said police refused to let him accompany Alfie Meadows out of the police cordon around Parliament Square.

The 20-year old Middlesex University student needed emergency surgery after suffering bleeding on the brain.

Prof Hallward came across Mr Meadows shortly after the incident in Westminster Square.

He said: “He was looking for a way out and looked shocked and dazed and had a bump on his head. It was not a cut but an impact wound – he had been hit by a truncheon, it seemed.

“I grabbed his arm and took him to the exit and the police let him go. We had been trying to get out ourselves but it was not easy.

“They would not let us accompany him. We did not know how bad the injuries were.

“He made a call to his mother who was in the demonstration and she heard the call and managed to press the police to let her through.

“If she had not heard that call and they had not found that ambulance it's quite possible he could have died in the street.

“The fact he got hit over the head at a demo is absolutely outrageous.”

He said Mr Meadows regained consciousness this morning and could talk and recognise his mother, and was now in a stable condition.

He said police called him this morning about the incident and he would file an official complaint later.