(Reuters) - Australian Olympic Committee President John Coates has said that allegations of bullying levelled against his long-serving lieutenant Mike Tancred are part of a "vindictive" campaign aimed at bringing his 27-year reign to an end.
Coates, an International Olympic Committee vice president and one of the most powerful sports administrators in the world, is facing the first challenge to his leadership since he assumed the role in 1990.
Olympic hockey gold medallist Danni Roche is standing against Coates in the presidential election at the annual general meeting on May 6.
In a letter to the AOC executive and national sporting organisations, and published by News Corp., Coates said the bullying allegations were defamatory, false and "maliciously" published, Australian Associated Press reported on Tuesday.
Media and communications director Tancred is the subject of a formal complaint by former CEO Fiona de Jong, who departed the AOC in December. She told local media the AOC was dragging its feet on an investigation into her complaint.
Ryan Wells, another former AOC staffer, has detailed a separate allegation of bullying against Tancred when working in its media department in 2004.
Tancred declined to comment when contacted by Reuters about the allegations. [nL4N1HW33U]
Coates said the complaint had been dealt with as a matter of "urgency".
"Specifically regarding the complaint made by Fiona De Jong, I assure you due process has been followed and followed with urgency," he wrote.
Coates said he was disappointed by a "malicious" campaign against him.
"There is clearly a coordinated and sadly vindictive campaign to damage me personally, and to tarnish all that has been achieved at the AOC," Coates said in the letter.
"This campaign is as disappointing as it is unfounded."
Coates said an AOC executive meeting that has been called for this week would be a "sensible discussion" about the issues.
Coates, a former rowing cox, played an integral role in Australia winning the right to host the 2000 Summer Olympics in Sydney and delivering a highly successful Games.
The 66-year-old is also the head of the IOC's coordination commission for the 2020 Tokyo Olympics and president of the Court of Arbitration for Sport.
He has, though, become embroiled in a public feud with the Australian Sports Commission (ASC) head John Wylie since the Rio Olympics and has accused the head of the Australian Institute of Sport (AIS), Matt Favier, of plotting to depose him.
Coates' opponent in the election Roche, who sits on the board of the ASC, has said her goal would be to build bridges between the various stakeholders in the Australian sports environment.
She has also taken aim at the A$700,000 Coates receives each year as a consultancy fee, saying she would work for free.
Writing by Peter Rutherford; Editing by Sudipto Ganguly