Watch: Dillian Whyte calls Joseph Parker 'coward' to his face, says he 'let down' NZ and family

Dillian Whyte clearly tried to get under the skin of Kiwi heavyweight boxer Joseph Parker, calling into question his "warrior spirit" after his unanimous loss to world champion boxer Anthony Joshua.

The pair will face off next Sunday 29 July (NZ Time) at London's 02 Arena.

The British boxer criticised Parker in their 'Gloves are off' interview saying he was running in his unification bout with Joshua in Wales in April, where Joshua ended up walking away with the Kiwi's WBO heavyweight title.

"He had his whole country over doing the haka, doing this and doing that and then he let them down," said Whyte.

"He didn't show the warrior spirit or warrior courage that I expected from him, from where he is from.

"He never showed that tribal instinct and that warrior instinct."

Whyte went on to say that Parker disappointed his family and country.

"You're desperate now, you let your family down and you let your country down."

Parker told his opponent that the fight helped his family.

"I didn't let anyone down I am set for life," said Parker.

The 30-year-old Englishman egged Parker on to come forward in their bout in London.

"Just don't be a coward in the fight and come and fight," said Whyte.

"Who is the coward?" asked Parker.

"You," responded Whyte.

"A coward is a person who calls someone a coward," said the Kiwi fighter.

Whyte fired back straight away with a comeback of his own.

"That is nonsense a coward is someone who doesn't show courage who needs to show courage."

"Well who got knocked out?" asked Parker, referring to the 2015 loss where Whyte was knocked out in the seventh round by Joshua.

"Because I wasn't a coward that's why, you were a coward that's why you didn't want to get knocked out and take chances," explained Whyte.

Parker and Whyte share similar professional records with the Kiwi winning 24 fights with only one loss, with Whyte winning 23 professional bouts with one loss to Joshua.

Parker is ranked sixth in the WBC, the title which American fighter Wilder holds. He is also ranked sixth in the WBO and seventh in the IBF, titles which both Joshua holds.

Whyte is ranked number one in the WBC, seventh in the WBA, another title which Joshua holds and second in the WBO.

The pair will face off next Sunday (NZ time) at London's 02 Arena.