A group of ex-sportsmen and women taking legal action claiming they suffered brain injuries during their careers has grown to 380, with former Wales rugby union international Dafydd James among the latest to reveal he has been diagnosed with early onset dementia.

James, who won 48 Wales caps and toured Australia with the 2001 British and Irish Lions, is among a group of former players to join a lawsuit against World Rugby, the Rugby Football Union and Welsh Rugby Union.

According to legal firm Rylands Garth, which has issued proceedings, a total of 380 sportsmen and women are now part of the group, with the latest additions featuring 100 rugby league players, 40 rugby union and 15 footballers.

James, former Manchester United defender Colin Gibson and ex-St Helens and Leeds Rhinos forward Nick Fozzard have decided to speak publicly.

More than 35 former players across both rugby codes had previously outlined their struggles. That list includes the likes of former Wales captain Ryan Jones, England World Cup winner Steve Thompson and ex-New Zealand prop Carl Hayman.

“Claimants contend that the defendants were negligent in failing to take reasonable action in order to protect players from permanent injury caused by repetitive concussive and sub-concussive blows,” Rylands Garth said.

“Many players now suffer from various irreversible neurological impairments, including early onset dementia, CTE (chronic traumatic encephalopathy), post-concussion syndrome, epilepsy, Parkinson’s disease, and motor neurone disease.”

James, 47, told the BBC that he had also been diagnosed with likely CTE.

“In a way it probably highlights that I’ve got a little bit of an answer about why I feel the way I do,” said James, who has had mental health issues.

“I suffer with my mental health, and in a way it’s quite cathartic to tell people because I am trying to help other people who are suffering, and there are plenty of people out there who are suffering.

“To the guys who are suffering, I think knowledge is key to understanding. I just think that knowledge is key and I think it’s important that people practice with care.

“Long may the game survive and thrive. I’m certainly not one of these people that wants to see the demise of the game. It’s given me so much pleasure.”

World Rugby, the RFU and WRU said, in a joint statement: “We care deeply about every member of the rugby family and have been saddened by the brave personal accounts of Dafydd and other former players who are struggling with health issues.

“Whilst legal claims prevent us from speaking to Dafydd directly, we would want him and his family to know that we care, we listen, and we never stand still when it comes to further cementing rugby as the most progressive sport on athlete welfare.

“Acting on the latest science, evidence and independent expert guidance, we constantly strive to safeguard and support all our players – future, current, and former.

“Rugby is a leader in the prevention, management and identification of head impacts, and World Rugby also proactively funds transformational research, embraces innovation and explores technology that can make the sport as accessible, inclusive and safe as possible for all participants.”