Lee Korsitz, the Israeli most likely to win gold in this summer's Olympics, has undergone surgery for an mysterious health problem unrelated to sport.

The women's windsurfing world champion is missing this week's European Windsurfing Championships in Portugal. She is unlikely to return to full training before April, raising major concerns as to whether she will be fully fit in the summer.

Korsitz, 27, is the only Israeli to win world titles twice. She won gold in Spain in 2003 and repeated the feat in Australia last December.