The 26-year-old was sent off for the fourth time in his career in The Magpies' 3-0 defeat to Liverpool at Anfield on Sunday.
Toon Suspend Barton After Major Bust Up!
Barton was dismissed for a reckless challenge on Xabi Alonso, and although Newcastle have not divulged the reasons behind Barton's suspension, it is believed to stem from an alleged bust-up between Shearer and the midfielder.
This latest move by The Magpies is almost certain to end Barton's career on Tyneside after he was backed by the club following his release from prison last summer.
The official statement: "Newcastle United can confirm that Joey Barton has been suspended from the club until further notice.
"The club will be making no further comment on the matter at this time."
The Sun reported yesterday: "Alan Shearer had a massive dressing-room bust-up with Joey Barton after Newcastle's 3-0 defeat at Liverpool.
"Shearer was steaming at the bad-boy midfielder for getting sent off for an ugly late lunge at Reds rival Xabi Alonso.
"But as the Toon boss tore into the £5.8m player, telling him he had let himself and the club down, Barton replied: "You're a s*** manager with s*** tactics."
"The pair went head to head and had to be pulled apart just as they were about to come to blows.
"A Newcastle insider said: "It was unbelievable. They were like two stags.
"Shearer told Barton he had made a mistake putting him back in the team, that he thought Barton was good enough to do it but he had shown he wasn't.
"Joey shouted at Alan that he was the best player at the club, which was why he had to play him.
"Alan said he wasn't, called him s*** and Joey replied that he was a s*** manager with s*** tactics.
"At that point, it looked like they were going to have a full-scale brawl and had to be dragged apart.
"Shearer was really angry, not just because of the stupid red card but because it means Barton will be missing for the last three Premier League games when Newcastle need everyone available.
"Alan gave Joey the big build-up during the week, saying what an important player he could be in Newcastle's fight against relegation, and then he does that.
"You wonder what goes on in Joey's head."