Boxer Anthony Mundine has climbed into the ring for outspoken Olympian John Steffensen, who claims he was racially vilified by an Athletics Australia official.

Steffensen is in London to contest his third Olympic Games after qualifying to run in the 4x400m relay.

The runner, whose parents are from South Africa, says he has been vilified throughout his career because of the colour of his skin.

A few days ago Steffensen, who won a silver medal at Athens, threatened not to run at the London Games, and overnight he missed the official team photo.

But he now says he will stay and compete.

Controversial boxer Mundine told triple j's Hack program that Australia is a racist country, especially on the sporting field.

"There is racism everywhere in this country. Australia is one of the worst racist countries in the civilised world to be honest ... there is no equality," he said.

"I think there is racism in sport across the board."

The former NRL star is a friend of Steffensen's and says the Olympian is devastated about the way he has been treated and that he was not selected as the first choice to run the individual 400 metres event.

"This is a lifetime dream for any athlete to compete in the Olympics, especially in his golden event which is a 400 individual and which he dominated all year," Mundine said.

"And now they pick a guy who hasn't raced all year and put him in before him.

"He's got the form, he's done everything right, but they can't answer for it."

Mundine says Steffensen is not the kind of man who would make up claims of racism.

"He can judge it like any human being and if he feels that way then obviously there is something wrong," he said.

Mundine says Steffensen confided in him about an incident that happened in Beijing and that Steffensen should be speaking out.

"Because that's what's going to make change, if you don't say nothing then nothing gets done," he said.

"They'll hold grudges against him, but he will get a lot more respect from the people all round."

In control

On Monday Australia's athletics captain Steve Hooker confirmed Steffensen's claims that there was an incident with an official when they were bunking in the same room in 2008.

But Australia's chef de mission Nick Green has downplayed the saga, saying it may just be the way Steffensen prepares for the Games.

He said his door was open to Steffensen if he wished to discuss the matter but also indicated other factors may be at play.

"Athletes prepare in different ways," Green told reporters on Tuesday morning (local time).

"If this is the way that John prepares best then that's the way he prepares best.

"I'm not going to interfere in the way John prepares."

Hooker had expressed his concerns about the issue being a distraction for the team's preparation for London competition.

But Green says he will not intervene until it gets "out of control".

"I don't know any of the details. AOC were not aware of the matter in 2008, it's come as a surprise to us," he said.

"This is the first they've heard of it when it was raised at the press conference.

"(Is he) destabilising the team? From the larger team point of view, no he's not.

"John Steffensen, we've said this along, he's a member of our team, he's welcome in our team. He's entitled to his comments.

"At the same time there are some really exciting things in the sport and within a team of 410 athletes we take a balanced approach in looking after all our athletes."

Mundine says he will be supporting Steffensen in the lead-up to his race in London.

"I'm going to try and reach out to him again, definitely, he's my boy," he said.