Police and prosecutors will decide whether to press charges against the protester who interrupted Tony Blair's evidence to the Leveson Inquiry.
David Lawley Wakelin, 49, burst into Court 73 at the Royal Courts of Justice yesterday where he accused the former Prime Minister of being a war criminal.
Lord Justice Leveson ordered an investigation and today updated the Inquiry on its progress.
He said: "Yesterday morning a man by the name of David Lawley Wakelin interrupted and disrupted the proceedings of this Inquiry for purposes of his own.
"I directed that an inquiry should take place and it has how been completed.
"Appropriate measures to prevent any risk of repetition have been taken.
"It is of critical importance that witnesses can give evidence without disruption of any sort and in those circumstances I am today referring this incident to the Director of Public Prosecutions and the Crown Prosecution Service who, in conjunction with the Metropolitan Police Service, can decide the way in which the matter can be dealt with appropriately."
Lord Justice Leveson gave his update just before Education Secretary Michael Gove, the second of today's witnesses, prepared to take the oath and give evidence.
The high court judge appeared angry yesterday when Mr Lawley Wakelin managed to evade security and access the court room through a back corridor.
The intruder, who made a film called The Alternative Iraq Enquiry, brought proceedings to a halt by hurling accusations at the former Prime Minister.
He said: "JP Morgan paid him off for the Iraq war. Three months after he invaded Iraq they held up the Iraq bank for 20 billion.
"He was then paid six million dollars every year and still is from JP Morgan six months after he left office.
"This man is a war criminal."
He was eventually wrestled to the ground by three men, ejected from the courtroom and arrested.
Mr Blair denied the claims.
Lord Justice Leveson, who rose to his feet when the intruder entered dressed in white shirt and trousers, called for an immediate inquiry, saying: "I would like to find out how this gentleman managed to access the court through what's supposed to be a secure corridor, and I'll have an investigation undertaken about that immediately."
Scotland Yard said Mr Lawley Wakelin was arrested on suspicion of breach of the peace and was held in custody at a central London police station. He was released without charge.
He said later that it was "surprisingly easy" to get into the court.
He told James O'Brien on LBC 97.3: "I just went ... up the back stairs and found that there was no security at all and in fact the door to the court was wide open in the same way that LordLeveson himself would have got in there."
It was "a little unnerving" to find himself suddenly in the spotlight, he said, but that he decided his "beef with Tony Blair is too great to miss this opportunity".
The police asked him to stay away from the rest of the Leveson Inquiry and he intended to obey that order, he said.