World heavyweight boxing champion Tyson Fury is suing Britain's anti-doping and boxing authorities over allegations that he used the performance-enhancing drug nandrolone.
The legal team for the both Fury and his cousin, Hughie, who was also accused, said "Team Fury" had issued proceedings in the High Court.
"The two boxers strenuously deny taking any performance-enhancing drugs. However, during the last five weeks, leaks about these charges have appeared in the press and both boxers have been the targets of continual abusive language on Twitter," lawyer Lewis Power said in a statement.
The Sunday Mirror reported on 26 June that traces of the banned substance nandrolone were found in a urine sample taken from Fury in April 2015 by UK-Anti-Doping, the body used by the British Boxing Board in the UK for random blood and urine testing of its licensed boxers. The test in question was in fact in February 2015.
The 27-year-old denied the claim at the time and his legal team said on Tuesday that the result of further tests from March and May in 2015 were contradictory.