English pop star Robbie Williams has opened up about losing his friend, cricket great Shane Warne, who died from a suspected heart attack in Thailand, aged 52.

Warne's body was returned to Australia overnight. 

Williams told ABC News Breakfast Warne transcended sport.

"I don't think words do death justice, and words could never do the passing away of such an icon justice," he said. 

"I won't even attempt them, but I will say this, and I mean this with a 1,000 per cent sincerity: There is a lot of tribalism in sports, it is what it is all about. Seldom does somebody transcend their sport and transcend that tribalism because it's genetically encoded in us to hate the other lot. 

“With Shane, he belonged to everybody. 

"And he did that thing, and he had that thing, that quality, that just lifted him several levels above everybody else as a personality, as a heart, and as a soul.”

Williams said Warne’s death made him reassess his own life.

"It's so massive when something like this happens that makes you take stock of where your life is, who you are, what you are, and what you want to be and what you want to do with your day, and what you want to do with the rest of your life. 

"My condolences, deep condolences to all his friends and family."

Williams will be in Australia next month filming a biopic, and will perform in Melbourne for one night only, April 30.

He said the show, and audience, would be filmed for inclusion in the film.

"I would like people to also come down in their best 90s clothing, if at all possible, because this particular part in the movie is set in the 90s. 

"And as a thank you, I will be doing several of my hit," he joked, possibly referring to Better Man, which is also the name of the movie.

Off the back of the ABC’s Anxiety Project, Williams was asked about the anxiety he experienced as a member of Take That.

"Anxiety isn't something that I dropped off at the train station when I left Take That," he said.

"Anxiety is something that you keep with you for life in one way or another. 

"It is with me anyway, and you cope with it the best you can."

He said anxiety could be difficult to manage, but having a sense of how you managed to get through a situation previously could make things easier.

"When you've got anxiety, your mind lies to you," he said. 

"And it tells you that you should be so fearful about the impending doom that is about to happen to you, that you should run away.

"So you are constantly in a flight situation. You want to run away, you want to hide, you want to be agoraphobic, you don't want to see people, you want to isolate — you want to do all of these things.

"And then, after a bit of time on the planet, you realise that you did all of these things that your mind said that you couldn't do and you didn't die.

"And I think that for me, particularly as a 48-year-old, I have found solace in the understanding that my mind said this, but that didn't happen.

"And unfortunately, it's part of a lot of people's journey on the planet.

"And managing it and maintaining it — this out-of-control beast that sometimes feels like you're not in control of — it has been a lifelong project, and it will carry on being a lifelong project."