John Obi-Mikel threatened to break Mark Clattenburg's legs and tried to aim a punch at him in the aftermath of Chelsea's notorious defeat against Manchester United last season in which the referee was accused of racially abusing the Chelsea midfielder.
That's according to an explosive serialisation of fellow ref Mark Halsey's upcoming autobiography serialised in the Sun on Sunday today.
The Durhmam official didn't take charge of a game for four weeks after the accusation was lodged, while Mikel was banned for three games and fined £60,000 for his role in the controversy and the bust-up after the game.
It was alleged that after the game Mikel had to be restrained by a group of Chelsea players and officials including then manager Roberto di Matteo - something that Halsey has now backed up in extracts from his book 'Added time: Surviving cancer, death threats and the Premier League'.
He wrote: 'My information was that Mikel stormed into Mark's dressing room when he was told about the remark after the game, shouting: "I'm going to break your legs. You called me a f****** monkey".
'He tried to land a punch on Mark but was pulled away by a combination of the Di Matteo and assistant Eddie Newton and Mark's three officials, fourth official Mike Jones and assistants Mick McDonough and Simon Long.
'Even before Mark had left Stamford Bridge that night, the press were knocking on the door of his home. The problem was that he could say nothing in his defence as part of legal advice and clauses in our contracts.'
'I took matters in my own hands and rang Sir Alex asking him to speak out. He agreed and used his Friday press conference to say he could not conceive of Mark saying such things. It helped the situation a great deal.'
Clattenburg has never spoken publicly about the incident and took charge of a Chelsea game five months after the incident occurred.