Sutton United have accepted the resignation of reserve goalkeeper Wayne Shaw, who is under investigation for potentially breaching betting rules.

The Gambling Commission and Football Association are investigating if there was a breach of betting regulations after the 45-year-old ate a pie during Monday's FA Cup loss to Arsenal.

A bookmaker had offered odds of 8-1 that Shaw would eat a pie on camera.

"What happened didn't make us look very professional," said boss Paul Doswell.

"It's something that we've dealt with quickly as a club," he told Sky News on Monday. "Wayne himself offered his resignation to the chairman this afternoon, which has been accepted.

"It's a very sad end to what has been a very good story."

Shaw, who said he was aware of the betting promotion prior to the match, played the incident - in which he ate the pie while standing by the substitutes' bench - down as "a bit of fun".

"We are told we are not allowed to gamble as it is full-time professional football," Shaw told BBC Radio 4's World at One programme. "In no way did I put anyone in jeopardy of that - this is not the case here, this is just a bit of fun and me being hungry."

However, the Gambling Commission confirmed it was looking into whether there was any "irregularity in the betting market and establishing whether the operator has met its licence requirement to conduct its business with integrity".

"It's clear in FA rules that you're not allowed to bet - and whether it was a fun bet, or whatever it was, it wasn't acceptable," added Doswell.

"Obviously we were very concerned with the implication that the club, myself, my assistant Ian Baird or anyone else had been involved in the decision-making.

"It's been very disappointing, there's no doubt about that. I woke up this morning to this storm of criticism.

"It's with a very heavy heart, because he was a good friend of mine, but I think the board felt they had no other choice."

Analysis

Joe Wilson, BBC sports correspondent

What happened at Sutton United might have seemed like a joke but it's clear that both the FA and the Gambling Commission are taking 'piegate' very seriously.

Wayne Shaw has stated that he didn't place a bet himself, but it's also clear than somebody must have done. Sun Bets used their own Twitter account to publicise that they had "paid out a five figure sum". The fact that Mr Shaw might have consumed a pasty rather than a pie (as he maintains) clearly was not a barrier to paying out for the betting company.

Anyone in Sutton United's playing and non-playing staff is covered by the FA's rules which forbid betting on any football match. The FA also makes it clear its rules cover 'football related' bets and the passing on of any insider information.

Typically any breaking of these rules results in a fine. for example in November Newcastle United midfielder Jack Colback was fined £25,000 after accepting a Football Association misconduct charge related to betting.

In information provided by The Professional Footballers Association for its members there is also a warning that breaking rules in regard to betting could be a criminal offence.

There is then the responsibility of betting companies to report any suspicious or unusual betting activity. This is the way all sports would seek to guard against a manipulation of their matches and outcomes, to prevent a collusion between players and fixers.

The gambling commission regulates the betting industry in Great Britain. In regard to the Sutton United v Arsenal match it is ''…looking into any irregularity in the betting market and establishing whether the operator has met its licence requirement to conduct its business with integrity".

The 'novelty market' is a general trend which concerns the Gambling Commission. In June last year it sent a general letter to bookmakers warning that standards should be upheld as it was concerned novelty bets could be "harmful to the wider perception of gambling in Great Britain".