Taiwan Wednesday rejected a Chinese plea to allow a visit by top World Bank official Justin Lin, who was born on the island but defected to the mainland over three decades ago.

The Taiwanese defence ministry said Lin, the bank's senior vice president and chief economist, remained a wanted person after swimming to China as a young military officer in the late 1970s.

"Lin has been placed on the wanted list of the Military High Court. Should he come back, he would immediately be arrested in accordance with the law," Taiwan's defence ministry spokesman David Lo told reporters.

He made the remark in reaction to an appeal by Beijing's Taiwan Affairs Office earlier in the day to let Lin visit to meet relatives and pay respects to his ancestors.

"The matter is several decades old," the office's spokesman Yang Yi said, according to a transcript. "We hope that the relevant authorities in Taiwan will allow Lin and his wife to visit out of humanitarian concerns."

Taiwan's defence minister Kao Hua-chu last week made clear his objections to the proposed visit.

"Lin is a still a lawbreaker. There is no room for being vague in this matter... I insist on this," Kao said, adding he would step down if Lin were to return and Taiwan failed to act.

Lin was a 26-year-old company commander in the Taiwan military stationed on Kinmen island near the Chinese mainland when in 1979 he swam the 2,000 metres (yards) to the communist side.

He arrived in China at the dawn of its opening up under Deng Xiaoping and played a key role in the country's economic modernisation before taking up his international career.

For many years Lin was not officially listed as a defector but as "missing", as his flight was considered an embarrassment.

However in 2002 he was put on a wanted list after he applied to return to Taiwan for his father's funeral.

The crime of defection is punishable by death in Taiwan.

Taiwan and China split in 1949 after a civil war but Beijing still claims the island as part of its territory awaiting unification, by force if necessary.