Gracie is a member of the family who invented the ground-fighting style.

It was the second time Warren had attended one of Gracie's two-day seminars, and he said he was surprised to be graded.

"It's a very big honour for me," Warren said.

"He's been one of my heroes since I was 16.

"I was very surprised as I just attended to learn some new skills.

"He approached me and said 'I'm grading you to blue belt' – a level that takes two years to achieve."

Warren, who also teaches jujitsu, said he took it up as a new challenge after achieving highly in taekwondo.

Warren has also achieved four belts in two gradings under the Japanese style jishin jujitsu.