Detectives investigating the unprovoked attack on the vice-chairman of the Northern Ireland Policing Board in a bar in the Brandywell, Derry, believe the assailant is an associate of a dissident republican group.
Denis Bradley (59) sustained lacerations and a suspected broken nose when a hooded man struck him several times on the head with a baseball bat as he was watching the UCD versus Derry City League Cup final on television in the Bluebell Bar on Tuesday night.
Sitting beside Mr Bradley was his 17-year-old son Owen. The bar, which is frequented by many Derry City supporters, was crowded for the cup final.
Police believe associates of an independent republican group were in the bar when Mr Bradley arrived with his son.
Shortly after their arrival, the attack took place.
Mr Bradley, a former priest who was a secret conduit between the Provisional IRA and successive British governments for almost 20 years, collapsed on to the floor after he was attacked. His assailant then ran from the bar.
When police officers arrived, a group of youths threw petrol bombs, stones and fire-crackers at them. One person was arrested for questioning about disorderly behaviour.
It is believed that Mr Bradley originally went to another bar on Culmore Road with his son to watch the match but that bar was not screening the cup final.
They then arrived at the Bluebell Bar and, having arrived late, both were seated immediately inside the entrance.
Since he became vice-chairman of the Policing Board several years ago, Mr Bradley's home in Park Avenue, in the Rosemount area of Derry has been attacked on several occasions by petrol bombers.
Following a petrol bomb attack on his home last year, a security screen was erected around the family home and a reinforced door and windows were also installed.
As family members and friends of the Bradleys visited Mr Bradley in hospital and sympathised with his wife, Mary, at their home yesterday, there was widespread condemnation of the attack.
SDLP leader Mark Durkan visited Mr Bradley in hospital on Tuesday night, as did Sinn Féin's chief negotiator Martin McGuinness.
Mr McGuinness said that he unreservedly condemned the attack.