The Association of Surfing Professionals (ASP) has been forced into an embarrassing admission that it made a mistake this week when it declared Kelly Slater had won this year's world title.

ASP, the sanctioning body that governs the world tour and pro ranking system, Friday admitted a calculation error that prematurely crowned Slater as the 2011 ASP World Champion.

In a press release, ASP World Tour manager Renato Hickel said, Our rankings system is designed to split tiebreaks based off of seed points. Kelly (Slater) and Owen (Wright) tied at best nine of 11 results, so we went to best eight of 11 results and the system gave it to Kelly based off his higher seed position. We were operating under that assumption and created the ASP World Title scenarios based off of that. This was a mistake. In the end, we're responsible for this and should be held accountable. We apologize to our fans, the surfers and to Owen and Kelly.

Initial rumor of the development hit the Web Friday morning when Slater tweeted a picture of a thread on Stating, Can you read this comment from mark? The calculator at @aspworldtour must be broken. I'm no the world champ yet!

Slater tweeted again: I'm not joking. I have not won the world title yet. I still have to win another heat! Give those shirts and hats back!

He needs to win one more heat, either at San Francisco or the season-ending event in Hawaii, to be assured of the title. Slater, far and away the most successful surfer the sport has seen, became the youngest man to win the world title when he won his first in 1992 aged 20.