Football agent Willie McKay is at the centre of more controversy over his role in QPR captain Joey Barton’s free transfer from Newcastle. The paperwork for the deal shows that McKay, who has had a turbulent relationship with the football authorities, acted for QPR in the negotiations, while Barton represented himself, with the terms signed off by the Rangers financial director Rebecca Caplehorn. The arrangement has surprised Newcastle, who are understood to have made their concerns known to the FA. Uncertain role: McKay McKay was active on Barton’s behalf during the summer saga that ended with the player leaving Tyneside to take up the £60,000-a-week on offer at Loftus Road. McKay working on behalf of QPR, rather than Barton, in the final negotiations would mean the midfielder would not be liable for any benefit-in-kind tax payment for his considerable agent’s fee. The Inland Revenue are aware this regulatory loophole surrounding dual representation is being exploited. McKay was one of five men arrested on suspicion of conspiracy to defraud and false accounting in November 2007 as part of the City of London Police football corruption probe. But 18 months later, he was cleared of any wrongdoing. In December 2008, he was given a suspended ban by the FA for breaching regulations by acting for two different clubs in two consecutive transfers of Portsmouth and Manchester City striker Benjani. QPR, Newcastle and the FA would not comment. McKay was unavailable