Australia's National Rugby League have blocked a move by the Brumbies to employ former Australian rugby league international Danny Buderus as their tackling coach.
The Brumbies announced early on Thursday that they had signed Buderus, who has played 24 internationals as as a Collision Coach for the 2013 Super Rugby season.
The Canberra Super rugby franchise said that Buderus would maintain his position as a player with the Knights in the NRL and travel to Canberra one day a week through to the start of the NRL season to coach tackle-specific skills.
Buderus said in the announcement, "Coaching is something I've always thought would be an interesting way to keep a connection with sport once I'd finished playing and this opportunity certainly allows me to start the ball rolling."
However the NRL reacted swiftly and sought an explanation from Buderus's Newcastle Knights NRL club in relation to an announcement.
"Neither Danny Buderus nor the Knights have sought permission from the NRL to enter into a third party agreement as his playing contract requires and as the club is required under the salary cap rules," acting NRL Chief Executive Shane Mattiske said in a statement.
"It is hard to envisage any circumstance where an agreement could be approved that allowed a current NRL player to promote another code competing in the same market as an NRL team."
Brumbies coach Jake White, the former South Africa World Cup-winning coach wanted Buderus to help improve his team's defence in his second season at the Brumbies and saw the former 34-year-old Test hooker as the perfect mentor to make that happen.
In 15 years as a league player, Buderus captained New South Wales to their last State of Origin series win over Queensland in 2005, won an NRL Grand Final with the Knights in 2001 and an English Super League title with Leeds in 2011.
The Brumbies are curently in their second week of pre-season training, with the first competition game against the Reds at Canberra Stadium scheduled for 16 February.