Republic of Ireland boss Martin O'Neill has accepted responsibility for the reported bust-up between Roy Keane and Harry Arter.

The Sunday World reported O'Neill's assistant Keane launched an expletive-laden rant against Arter after the midfielder sat out a training session at a team camp in June.

According to reports, a leaked WhatsApp message, said to have come from Stephen Ward, detailed the row between Keane, Arter and forward Jon Walters, who had also been advised to miss the session by medical staff.

O'Neill appeared to confirm Burnley defender Ward was the source of the message after questioning how the 33-year-old would have first-hand knowledge of an incident he did not witness.

He also took responsibility for any altercation between his assistant and Arter, who withdrew from the Ireland squad last week before the Nations League defeat to Wales.

"First of all, Stephen wasn't there; he's just picking up on things, something that we talked about at the beginning of the week," O'Neill told a news conference ahead of Tuesday's friendly with Poland.

"[There is] Probably not anything more to really report. I think there are differences over what was said, [but there was] a confrontation with Jon and a confrontation with Harry.

"Jon is fine, absolutely fine. Harry, perhaps not so fine. But I said to you before: you'd have to ask if that is the complete reason why Harry is not participating in these games this time. But I think you probably know that anyway because Harry has let it [be] known to a few people anyway, the reasons he has decided not to come.

"If you're asking about Roy's criticism of players, let me tell you: this is my responsibility, totally my responsibility, absolutely and utterly, as is every single kick players make, every save that is made, every corner that is conceded, every goal that is scored... they are all my responsibility.

"So, I'll take full responsibility for what has happened there in this camp. At the end of it all, I don't want to make too fine a point, I'm actually the manager. I've had in my time as a club manager, I've chosen two brilliant, brilliant assistant managers, two characters, two world-class players: John Robertson and the young man himself, Roy Keane. They're different but I've chosen them and at the end of it all, none of them have ever let me down.

"If there is a still a difference over what was said, I accept that at this minute, but I wasn't there myself and Stephen certainly wasn't. Whether he's picking up [his account] from other conversations, I'm not sure. I think some of you will have to speak to Harry about it and I think some of you do."