10:50am UK, Thursday October 06, 2005

The Beckhams have flown son Romeo back to Britain as they desperately try to find out what mystery illness he is suffering from.

The three-year-old has undergone tests in Spain after he suffered three fits in the last three months.

180 romeo beckham and mum

Romeo and his mum

The couple headed back to the UK on a private jet after Romeo spent a night in the Ruber International Clinic in Madrid.

Beckham, 30, has now joined his England team ahead of the two World Cup qualifiers against Austria and Poland.

But the pair are believed to be distraught over their middle-son's illness.

A close friend told the Daily Mail: "Victoria can't stop crying while David appears to have gone into a sort of shock.

"Romeo has had a number of tests and they are determined to get to the bottom of his problems.

"The little boy can't really understand what is happening and he has been very tearful. It's a heartbreaking situation."

Febrile convulsions are common in children up to the age of five and can be caused by the high temperatures which result from infections.

But on rare occasions they can be a symptom of more serious problems.