TOKYO (AFP) - Doctors who carried out surgery on a Japanese man to remove a "tumour" had good news and bad news for him. He did not have cancer -- but the "growth" that had been causing him pain was in fact a 25-year-old surgical towel.

The patient had been carrying the cloth since 1983, when surgeons at the Asahi General Hospital in Chiba prefecture near Tokyo left it in him after an operation to treat an ulcer, a spokesman for the hospital said.

The man, now 49, went in to another hospital in late May after suffering abdominal pain.

When examinations found what was believed to be an eight-centimetre (3.2-inch) tumour, he underwent the operation to remove it. It was only then that surgeons realised it was a towel.

"The towel was greenish blue although we are not sure about its original colour," the Asahi General Hospital spokesman said, adding it had been crumpled to the size of a softball.

Asahi hospital officials visited the man and apologised, he said.

The former patient has no plans to sue the hospital, which is in talks with him over compensation or other measures, the official said.

Japanese media reports said the man, who was not identified, still had his spleen removed.