London - Anthony Joshua has called for tougher rules to be put in place when boxers fail drugs tests in the wake of Jarrell Miller's six-month ban.

Joshua was set to defend his WBA, IBF and WBO heavyweight titles against Miller on June 1 at Madison Square Garden, but his opponent reportedly test positive for a number of performance enhancing drugs.

Andy Ruiz Jr has stepped in as the replacement for Miller, whose relatively short suspension from the WBA convinced Joshua to question whether enough is being done to combat doping in boxing.

"Maybe there needs to be more of a situation where it's not just a random six-month ban," Joshua was quoted as saying by British media on Wednesday.

"I know, for instance, if I carry a bladed article I'm going to get x amount of time in jail, if I carry a weapon of destruction I'm going to get a certain amount of time in jail, so you know (the consequences of what will happen).

"Six months is news to me, it's like 'why did he only get six months?' It should be 'Miller's definitely getting this', that's my opinion on it.

"There should be something where people know if they mess up, this is exactly what is happening."

When Joshua gets back in the ring for the first time in over eight months, he will now face Ruiz Jr, who is bidding to become Mexico's first heavyweight world champion.

California-born Ruiz Jr has won 32 of his 33 professional contests.

"The chills - I'm really excited for this fight," he said in a statement released by Matchroom Boxing.

He cited Mexican great Julio Cesar Chavez, a world champion in several lighter classes, and former heavyweight world champions Mike Tyson, Evander Holyfield and Lennox Lewis.

"This is my chance to make history, I want to be one of those greats like Chavez, Tyson, Holyfield, Lennox Lewis. I want to be in that category."

"I'm going to bring the titles back to Mexico. I'm going to be able to change my whole family's lives, my life and all my kids."

Ruiz's only defeat came in a world title challenge against New Zealand's Joseph Parker.

Joshua, 29, who has won all of his 22 fights, will be fighting in the United States for the first time.

"Ruiz is a different kind of challenge but one I embrace," said Joshua.

"We have worked in the boxing gym week on week and whomever is put in front of me at Madison Square Garden on June 1 will be dispatched in style. The rent will be collected."