The 51-year-old collapsed at Madrid airport on Monday and was taken to hospital in the city, where he was kept in intensive care while doctors conducted brain scans.

Ballesteros left La Paz hospital's intensive care unit on Saturday, before making the announcement about his condition yesterday after informing his family.

The statement released to the Spanish media began by announcing Ballesteros would undergo a biopsy tomorrow, saying: "The doctors will now decide how to proceed.

"Throughout my entire career I have been one of the best at overcoming obstacles on the golf course.

"And now I want to be the best, facing the most difficult game of my life, using all my strength and also counting on those who have been sending me get-well messages.

"Now I've been able to tell my three children personally and their mother, now I can tell you the illness that I am suffering from.

"After the exhaustive tests that I have undertaken in the Hospital La Paz (Madrid) they have detected a brain tumour.

"I have always sympathised with those people who face illnesses.

"Therefore, I want to remind them that with bravery, faith, serenity, confidence and a lot of mental strength, we have to face any situation no matter how difficult it is."

Ballesteros asked for his family's privacy to be respected while promising to keep people regularly informed of his condition.

"Now my wish is to ask for respect for my family and especially for my children.

"I want to thank from the bottom of my heart all those people who have shown affection and interest in my state of health, with all kinds of support. Many thanks."

Ballesteros is a three-times winner of the Open and won five majors and 87 titles in all. He also captained Europe to Ryder Cup success over the United States at Valderrama in 1997.

He announced his retirement from golf in July last year because of persistent back problems.