Van de Velde lost the 1999 Open in dramatic circumstances

The 2007 Open will take place at Carnoustie, the scene of Van de Velde's infamous last-hole collapse in 1999.

"I've been physically sick on occasions - including on the course during the Wales Open," said Van de Velde.

"I'm going back to have a camera put down my stomach and until then what bothers me is that they don't know."

606: DEBATE Surely the R&A won't deprive us of Van de Velde at The Open. He deserves an invite BM

Van de Velde said he started feeling ill at the end of March and doctors have been unable to diagnose his condition, although they suspect he has a virus or a bacterial infection.

"I've had several tests already with a specialist in London and they thought at first it might be a liver complaint which my father has also suffered from," he said.

"That could have meant draining half a litre of blood every week for a while, but the latest test came back negative.

"I have some good days and some bad days.

"I was planning to practise on Tuesday, but I didn't because I was a wreck. Anybody seeing me would have thought I was drunk."

The 41-year-old lost the 1999 Open in dramatic fashion, finding the water when he dumped his third shot on the final hole into the Barry Burn and eventually carding a triple bogey.

That meant he found himself in a play-off with Scotland's Paul Lawrie, who went on to become the last British player to win a major.

Van de Velde could yet reach Carnoustie by finishing in the top two in the French Open or coming through qualifying at Sunningdale.

And if Van de Velde does not qualify for Carnoustie at either the French Open or Sunningdale he has two more chances.

He would need to finish in the top two at either next week's European Open or the following week's Scottish Open.

A number of big names have pulled out of the French Open, which starts at Le Golf National near Paris on Thursday.

New US Open champion Angel Cabrera has decided to take another week off following his triumph, Darren Clarke has opted to play in the US and Jose Maria Olazabal and David Howell are both injured.