Newcastle United's Boxing Day brawl involving Jason Tindall and Aston Villa manager Unai Emery has seen new policies adopted at St James' Park after an Aston Villa director accessed the tunnel to get involved in the 'mass confrontation'.

An FA report revealed the inside story behind Tindall's red card, how he was approached by an irate Unai Emery and what unfolded in the tunnel - including how a Villa chief came down from the chairman's suite to fire up the incident just as it seemed to be calming down.

Tindall was sent to the stands during Newcastle's 3-0 victory over Aston Villa but the visitors have had coach Victor Manas banned from stadiums completely for two games for his part in the 20-man brawl. Tindall returned to the scene near the mouth of the tunnel with five minutes of the game left, donning a Wham hoodie - which appears to have pushed Villa over the edge.

READ MORE: Anthony Gordon, Dan Burn and six other injuries - Newcastle United return dates

READ MORE: Newcastle diehards buying Wembley final tickets vs Liverpool sent strong statement

The madness began when Jhon Duran was sent off in the first half for trailing his studs down Fabian Schar with Anthony Taylor issuing a red card, causing Manas to hurl abuse at the referee and Newcastle's coaching staff, according to the report.

In it fourth official Leigh Doughty, a Championship referee in his own right, said: "On route back up the tunnel at the half time interval, I witnessed Mr Victor Manas, an analyst of Aston Villa, shout aggressively and act confrontationally in the direction of Mr Jason Tindall, Newcastle's assistant manager.

"Mr Tindall was positioned at the top of the tunnel heading up the stairs and reacted confrontationally with verbals back to Mr Manas Then at the top of the stairs I saw Mr Tindall come face to face with Mr Unai Emery, Aston Villa's Head Coach, as a result of this verbal confrontation between Mr Manas and Mr Tindall.

"From that point, the mass confrontation occurred at the top of the stairs and into the area outside the changing rooms. As I got to the top of the stairs there was approximately 20 men involved. I witnessed Mr Tindall being restrained back by some Newcastle colleagues, clearly acting in an aggressive and confrontational manner.

"The referee, Anthony Taylor, then got back up the stairs and everybody settled down and went back into their changing rooms. Mr Manas remained and Anthony requested he came into the entrance of the officials changing rooms. Mr Manas was disputing the red card decision in the game. We acquired his full name and told him he would be reported for his conduct for instigating the entire mass confrontation with his initial verbal aggressive and confrontational actions. I also informed Anthony that Mr Tindall should be given a Stage 2 dismissal for his actions as the retaliator and not come out pitch side for the second half."

Villa complained to the FA about the hoodie but also brought Tindall's "behavior" from last January's 3-1 win for the Toon into their report. Mrs Sharon Barnhurst, AVFC Club Secretary said: "It should be noted that Mr Tindall also displayed this type of behaviour last season at our match at Villa Park."

And the secretary went on: "During the first half, the NUFC assistant manager, Jason Tindall, on 3 or 4 occasions was waving his finger and “shushing” our Head Coach, Unai Emery, in a very disrespectful and antagonist manner."

However, Newcastle stated to the FA that just as the brawl was calming down, Villa's director of football operations Damien Vidagany swapped the chairman's suite for the tunnel area, and escalated the situation.

Newcastle stated that the Spaniard, and former Valencia man, had got involved to make matters worse. They said: "The Club is now reviewing its matchday operations policy of allowing individuals with Director’s Box passes who also hold red-zone accreditation access the tunnel area at half-time or immediately after the full-time whistle."

The report had read: "DV throughout the incident was shouting loudly and confrontationally and was generally behaving in an aggressive manner. DV then escalated the incident by holding up his arms to stop those already gathered in the tunnel area from progressing to the changing rooms.

"This resulted in a large number of people being gathered in a small space. In undertaking this act, DV was walking backwards and fell into the stairs which lead up to the changing rooms. DV was uninjured but this made him act more aggressively and escalated the situation further."

An FA statement read:" Both clubs and Victor Manas admitted to their respective charges, and Jason Tindall denied the allegation against him. The Regulatory Commission imposed a £30,000 fine and warning upon Aston Villa, a £20,000 fine and warning upon Newcastle United, and a two-match ground ban and £4,000 fine on Victor Manas. The Regulatory Commission found the charge against Jason Tindall to be not proven, and he will face no further action."