The Rugby Football Union has been caught up in a bizarre artificial intelligence (AI) mix-up over criticism of Tom Curry's selection to face Japan on Sunday.

On Friday afternoon, the @EnglandRugby X account announced Steve Borthwick's line-up for England's fourth and final autumn international. Having passed relevant head injury protocols following the concussion he sustained against Australia a fortnight ago, Curry was named to start at blindside flanker.

Several users of the platform questioned the involvement of Curry on the basis that the back-rower had been knocked unconscious against the Wallabies. Close to 40 replies, some as straightforward as @matthewhoade69 stating "cannot believe Tom Curry is being included after his concussions", were subsequently hidden by @EnglandRugby.

Among the more robust replies that were hidden came from @RucksSake, who posted: "Absolutely disgusting bringing Tom Curry back in after being knocked out when in reality England win this game easily with or without him."

This led to suggestions that such sentiment was being intentionally suppressed. However, it is understood that the censorship was down to AI software known as Arwen, which is used to moderate racism and threats of violence.

A source described the hidden replies as "an honest mistake" caused by increasing the filter sensitivity on mentions of Curry's name last week, during the build-up to England's meeting with South Africa.

RFU staff had been wary of Curry being targeted by Springboks supporters after he accused Bongi Mbonambi of racially abusing him during last year's World Cup semi-final.

After the issue was highlighted on Friday evening, Arwen filters were altered in an attempt to keep criticism of the selection visible. X user David Hartley, posting from the handle @sharkbaitza, was among those to compose a reply that has not been hidden.

"It's disgusting that you are playing Curry in a friendly game with so much depth in that position after his concussion issues," Hartley wrote on Saturday morning. "Where is your duty of care to player welfare."

Borthwick was asked about Curry's inclusion as part of his press duties on Friday and explained that the 26-year-old had been thoroughly examined before being cleared for selection.

"The welfare [and] health of players is paramount," the head coach said. "He's gone through all those protocols, a number of different consultations, independent specialist consultations. He feels great, he's raring to go. The process has been very thorough."

The RFU has been approached for comment.