A trial of referees wearing body cameras in adult grassroots football will be doubled following "encouraging" results, with no incidents of abuse recorded in around 500 matches.

The presence of a bodycam has made players and coaches rethink their behaviour, the FA's head of refereeing Daniel Meeson told BBC Radio 5 Live.

The trial will be extended to include eight county associations in 2024.

But Meeson added more data must be collected before wider implementation.

Meeson, head of technical and referee development at the FA, said the trial - ongoing for the past seven months - would need to last two to three seasons for sufficient analysis and its success as a deterrent was "difficult to say at this stage".

He added that the use of bodycams was "a sad situation to find ourselves in" but the treatment of officials in the game had reached a stage where the FA "needed to do something pretty strong".

Approximately 100 grassroots referees have worn the equipment while officiating matches across Middlesbrough, Liverpool, Worcester and Essex, with recorded footage available for use in disciplinary hearings as appropriate.

Discussing the success of the trial to date, Meeson said: "There has not been an incident where a player has been insulting, abusive or offensive towards a match official - and nor has their behaviour prompted a match official to activate their device.

"Referees feel safer but more importantly the players and coaches are having a more enjoyable experience when they play the game.

"The players and coaches involved in the trial have said the mere presence of a bodycam has made them rethink their behaviour before saying something or acting in an inappropriate way towards a match official."

It comes after more than 900 referees in England responded to a BBC Radio 5 Live questionnaire earlier this year, with 293 saying they had been physically abused by spectators, players, coaches or managers

Some described being punched, headbutted and spat at, while almost all the respondents had experienced some form of verbal abuse.

The president of the Referees' Association in England said the abuse of match officials was having a significant impact on their mental health.

Bans were handed to 380 players and coaches for attacking or threatening referees and match officials in English grassroots football during the 2021-22 season.

"We are still in the infancy of the trial. We really need to run this out for two to three seasons to build a sufficient amount of data and insight that we can use to say whether it is successful or not," Meeson said.

"The FA are absolutely committed to exploring every avenue possible to afford an extra level of protection to our referees in the grassroots game, and to improve participant behaviour across the board," he added.

Meeson added that the FA are continuing to explore other measures to address poor behaviour, including tougher sanctions, education for persistent offenders, and deducting points "from clubs where players are continuing to behave badly".

The bodycams are available when the referee deems them necessary. Rather than recording the whole game, the device captures the previous 30 seconds of footage once the official activates it.

However, Janie Frampton, vice president of the International Federation for Sports Officials and chair of Ref Support UK, expressed concern over the ability to expand the use of bodycams.

"We have always said we wanted bodycams," said Frampton, also a former leading international referee.

"My concern is upscaling. The trial is using bodycams and the upscaling of that is incredibly expensive. I know that is a bit of a sticking point right now."