Tokyo 2020: UK Sport performance director Chelsea Warr quits six months before Games
UK Sport performance director Chelsea Warr has stepped down just six months before the 2020 Tokyo Olympics.
The Australian will join the Queensland Academy of Sport as chief executive later this year.
Warr, who joined UK Sport in 2005, was a key figure behind Great Britain's successes at London 2012 and Rio 2016.
In December, she said Britain could surpass their record medal haul from Rio in Tokyo, having finished second in the table in 2016 with 67 medals.
"We would like to thank Chelsea Warr for the significant contribution she has made to British Olympic and Paralympic sport over the past 18 years; both at UK Sport and prior to that at British Swimming," said UK Sport in a statement.
"We wish her every success in her new role in her home country."
UK Sport said deputy director of performance Michael Bourne has taken over on an interim bases to "ensure continued support for our performance team and sports as they complete their Tokyo preparations."
The body, which allocates funding to Olympic and Paralympic sports, added it will start searching for Warr's replacement.
BBC sports editor Dan Roan
Given Warr's reputation as one of the key figures behind Britain's remarkable emergence as a true Olympic and Paralympic powerhouse in recent Games, and her role leading the country's high-performance system, the timing of this announcement, coming just six months before Team GB makes its way to Tokyo, will stun many in British sport.
With much of the preparation already done, and Warr not able to take up her new role in Australia until after the Games, the impact on Team GB's fortunes in Japan should be minimal.
But she has also been leading performance plans for the next eight years however, and there will be concern that she is now going to a direct competitor.
So why now? Warr is known to have disagreed with her new boss - UK Sport's chief executive Sally Munday - in the past.
Warr was credited with developing the Talent ID scheme that helped discover a number of star athletes. But she was also closely associated with UK Sport's controversial 'no compromise' approach, linking medals to funding. For a long time it was hailed a success.
But in recent years a series of athlete welfare scandals have forced a change of direction, with more emphasis on duty of care. Some insiders believe with the departure of her former boss Liz Nicholl last year, and the cultural shift, Warr felt the organisation had moved on."