Police are today investigating allegations a referee was assaulted by a fan during a match involving a Norwich football club.

Officers were called to Norwich United's game at Cambridgeshire club Godmanchester Rovers after referee Daniel Hanna, who is also a policeman, was allegedly attacked on his way back to the changing room at the end of the game.

The issue of abusive behaviour at matches led to the launch of the Football Association's Respect campaign seven years ago.

A recent survey of 2.000 English referees by the BBC found that nearly two-thirds experienced verbal abuse on a regular basis, but a spokesman for the Norfolk FA has stressed that physical abuse towards referees and other match officials has fallen. A spokesman for Cambridgeshire police confirmed they were called to the Thurlow Nunn League match between Godmanchester and Norwich on Saturday.

'We were called to Godmanchester Rovers Football Club, in Bearscroft Lane, to reports that a man in his 20s had been assaulted. Investigations are ongoing,' the spokesman added.

The match saw Godmanchester run out 3-0 winners after two Norwich United players were sent off.

Keith Cutmore, secretary for Norwich United, said: 'I was putting the kit away in the car when one of their [Godmanchester Rovers'] committee members told me about what happened.

'I have never come across it before, we were all gobsmacked and didn't know if it was some sort of sick joke.'

Speaking about the incident, Godmanchester chairman Karly Hurst said club officials helped to detain the suspect in the club car park until the police arrived.

He added: 'It's a shame that something like that happened on such a good day for our club, but the referee has already sent us our thanks for assisting him afterwards.

'Whatever you think of referees, they go out and do a very difficult job.'

Despite the incident, Norfolk FA's administration manager Matt Carpenter said physical abuse towards referees and other match officials has dropped since 2013.

He said: 'The Respect campaign has been running for a number of seasons and it has had an impact, as statistically, the number of incidents are down.

'But in any given incident, if someone feels as though they are going to abuse a referee, it does not matter whether there is a respect campaign or not, because at that point they have lost all control.'

'The issue is an ongoing challenge and any assault on a referee is one too many.'

The FA's Respect campaign was launched seven years ago to improve behaviour among players and spectators.

Norfolk FA said last season there was just one reported offence of a physical assault against a match official.

There was also nine reported offences of improper conduct, which includes anything from pushing to grabbing a referee's notebook.

It was a significant drop compared to 2013-14, which saw 18 incidents of improper conduct and three assaults.

Mr Carpenter said the Norfolk FA was looking into Saturday's incident.