WBC heavyweight champion Tyson Fury said he is retiring from boxing on his 34th birthday on Friday, having previously performed a number of U-turns over his future in the sport.

"Massive thanks to everyone who had an input in my career over the years & after long hard conversations I've finally decided to walk away & on my 34th birthday I say Bon voyage," Fury posted on Twitter.

The announcement has been greeted with scepticism as Fury has previously stated his intention to retire only to return to the ring.

He was expected to fight the winner of Oleksandr Usyk's rematch with Anthony Joshua on August 20 for the chance to unify the world heavyweight titles.

As recently as Tuesday, Fury suggested his most recent spell in retirement was over in order to set up a trilogy fight against Derek Chisora and even claimed to have appointed a new trainer in Isaac Lowe.

However, he has now announced the intention to retire undefeated with a record of 32 wins and one draw from 33 bouts.

Fury went onto thank his wife, promoter Frank Warren and a series of other training partners and television companies who have bought rights to his fights over the years.

The Brit stated ahead of his win over Dillian Whyte in March that he would retire after that fight as he has "150 million in the bank and nothing to prove."

However, earlier this week, Warren had cast doubt on the suggestion Fury will not fight again.

"I think what's going to happen is, see what happens on 20 (August) and the outcome of that, and that'll determine what he intends to do in the future,' Warren told talkSPORT.

"I think he will (return), because he's a fighting man and he misses it. That's what he does, he wants to fight."