Four thrown out in France

The 2008 China Open winner Damien McGrane of Ireland was the highest-profile casualty of the quartet. South African Jaco Van Zyl, Rikard Karlberg of Sweden and Britain's James Ruebotham were also disqualified.

All sent balls into the lake at the 18th and then played from the wrong spot after taking a penalty. Because they left the recording area, unaware they had broken the rule, they were effectively disqualified for signing for a wrong score.

Players had been informed of the correct way to drop the ball at 18 in sheets handed to them before play and on notice-boards.

"One player said he had read the notice explaining how to drop the ball correctly but forgot it and the other three said they had not read the notice," European Tour chief referee Andy McFee told reporters.

"This rule was in force last year and we didn't have one disqualification. I'm bemused."

McGrane held up his hands, saying: "I didn't read the notices and my caddie misinterpreted them."

The four disqualifications happened during morning rounds. Rules officials kept an eye on the afternoon field and prepared to advise players if they saw them taking wrong drops at 18.

McFee said he did not consider it unfair that the four disqualified players had not had the same advantage.

"Sometimes we have a referee on a hole, sometimes we don't," he said.

It was the greatest mass disqualification since 1990 when six players were dumped out in the first round of the AGF Open at La Grand Motte, Montpellier, for removing out of bound posts - considered immovable objects - to play their shots.