Red Flag, which specialises in strategic communications and has offices in Dublin, Brussels and London, has several connections to Independent News and Media (INM), of which Denis O'Brien is now the largest shareholder.
He took control of the newspaper group after a power struggle with Sir Anthony O’Reilly.
Sir Anthony's son Gavin O'Reilly, who was named in the High Court action taken by Mr O'Brien, is the chairman of Red Flag, according to the company's website. He was formerly the chief executive of INM.
Karl Brophy, who established Red Flag and is its chief executive, was the former corporate affairs director at INM.
In October 2012 he settled a High Court action against his former employer.
In an agreed statement at the end of the case, counsel for INM confirmed no allegation of misconduct had ever been made against him.
Mr Brophy, the court was told, accepted the decision to make him redundant from INM was taken by its chief executive, Vincent Crowley, and Denis O'Brien had "no hand, act or part in that decision".
In his original injunction proceedings, Mr Brophy had alleged Mr O’Brien was behind the decision to dismiss him because of a history between the two men.
Mr Brophy had formerly been a journalist with the Irish Mirror and, in 1998, wrote an article which led to Mr O’Brien receiving €750,000 in damages.
Red Flag director Sir Ivor Roberts previously sat on INM's international advisory board.
Garret Doyle, Red Flag's chief operating officer, is credited on its website with launching independent.ie and co-founding Independent College Dublin.
