The Finnish veteran exploded into world title contention with his two career-best results - successive knockout wins over the previously undefeated Adam Kownacki.

'The Nordic Nightmare' Helenius is ranked at No 3 by the WBA, whose belt is held by Usyk, and he is demanding to be instated as the mandatory challenger.

"Right now we are waiting for a formal response from the WBA, this is my first priority," Helenius told Sky Sports.

"My lawyer has notified WBA in writing, I've paid sanctioning fees, and there is no more deserving contender to fight Usyk in the WBA than me.

"I fully expect to be officially named mandatory.

"I've earned it and I will fight outside the ring as hard as I fight inside the ring for my opportunity."

Usyk is set to defend his IBF, WBA and WBO heavyweight titles in a rematch against Anthony Joshua.

Britain's Daniel Dubois is ranked at No 1 by the WBA and is targeting a fight with Trevor Bryan, who holds the governing body's 'regular' belt.

Michael Hunter is ranked at No 2.

Helenius, who has shared the ring with Derek Chisora and Dillian Whyte, has also emerged as an unexpected option to face Fury.

Fury is in negotiations to defend his WBC belt against mandatory challenger Whyte but has not yet sealed a deal, despite naming March 26 as his preferred date to return.

Helenius and Andy Ruiz Jr were cited as alternatives to Whyte by Bob Arum, who promotes Fury in the US.

"I have heard my name mentioned by Bob Arum and others of possibly fighting Fury in March," Helenius said.

"Of course, I feel I would beat Fury.

"He looked great against Deontay Wilder, but he would find a much less favourable style against me.

"I would knock Fury out.

"He is an easier style for me than Usyk for sure."

The race to be named as mandatory challenger for each of the four governing bodies is on, as Fury gears up for his expected fight with Whyte and Usyk gets set to meet Joshua again.

Joe Joyce is ranked at No 1 by the WBO, Filip Hrgovic is No 1 with the IBF, and Whyte is the WBC mandatory challenger.

Helenius said: "I leave the business side to my manager Markus Sundman and our advisor Mike Borao - whoever comes, Usyk, Fury, anyone, I will be ready.

"I feel better now than ever in my career. I will win a world title."

Sky Sports Boxing schedule

Sunday January 16 - Top Rank in New York
Joe Smith Jr vs Steve Geffrard - WBO light-heavyweight title

Sunday January 30 - Top Rank in Tulsa
Robson Conceicao vs Xavier Martinez - WBC super-featherweight title eliminator

Saturday February 5 (targeted) - BOXXER in Cardiff
Chris Eubank Jr vs Liam Williams
Claressa Shields vs Ema Kozin - IBF, WBA and WBC middleweight titles

Saturday February 19 - BOXXER in Manchester
Amir Khan vs Kell Brook
Frazer Clarke's pro debut

Saturday February 26 - BOXXER and Top Rank in Glasgow
Josh Taylor vs Jack Catterall - undisputed super-lightweight titles

Saturday March 5 - Top Rank in Fresno
Jose Ramirez vs Jose Pedraza