Gardiner was set to fight in the last 16 of the super-heavyweight competition at the European Olympic boxing qualifying tournament in London in March last year before it was postponed due to the coronavirus pandemic.

The event is now scheduled to take place in April, but Gardiner will not be there after announcing his retirement.

Martin Fennessy, who coaches at Clonmel Boxing Club where Gardiner trains, confirmed the 32-year-old’s personal circumstances had changed following the postponement of the Olympics and the arrival of his first child.

"Dean returned to full time education last September doing a degree in business studies as planned thinking that the Tokyo 2020 Games would have been completed," Fennessy wrote in a social media post.

"Dean and his girlfriend Natasha had a bouncing baby boy Michael last year so a lot of life changes to juggle with 10 to 12 training sessions per week, some in Dublin and Clonmel Boxing Club.

With only so many hours in a day and the cancellation of the national senior elite championships this month and the uncertainty of boxing in general at the present time Dean called it a day."

Fennessy claims Gardiner has been Ireland’s number one international boxer for the past seven years, having represented his country at the European Games, European Championships and World Championships.

His decision to retire is another blow to the Irish Athletic Boxing Association (IABA), which was forced to postpone this month’s Elite Championships due to the global health crisis.

The IABA is hoping to hold the event ahead of the Olympic qualifier, which is set to take place from April 22 to 26 at the Copper Box Arena on the Queen Elizabeth Olympic Park in London.

Brendan Irvine is currently the only Irish boxer to have secured their place at Tokyo 2020.

Russian Ivan Veriasov, who was due to fight Gardiner in the last 16 in London, is set to receive a bye into the next round as Ireland will be unable to nominate a replacement.