An Auckland publisher embroiled in a tug-of-love case with his Turkish ex-wife over their 2-year-old son has had another setback.

Bruce Laybourn, 54, flew to Istanbul last week to spend a month with his New Zealand-born son, Dylan, under an interim access arrangement ordered by the Turkish courts. But he says when he arrived to take the boy to a rented apartment, his former wife, Nil, had taken Dylan into hiding.

The Foreign Affairs Ministry says the New Zealand Embassy in Ankarra will be contacting Turkish authorities "to express our expectation that Mr Laybourn's access rights to his son are upheld".

Mr Laybourn, who remains in Istanbul, has asked Turkish police to trace his son. "I am assured that my month's custody begins the day Dylan is returned - so the kidnap is a fruitless exercise."

Mr Laybourn has unsuccessfully fought for more than two years to have Dylan returned to New Zealand under the Hague Convention on child abductions. The pair met and married in New Zealand and were living together when Dylan was born in January 2007. But Mrs Laybourn failed to return to Auckland in May 2007 after taking their son to visit her family.

Because of a bureaucratic hurdle - Turkey had not officially recognised New Zealand's Hague Convention status at the time of the abduction - Turkish courts have refused to order Dylan's return to allow custody to be decided by the New Zealand Family Court, as the convention requires.

In November 2007, the Turkish Family Court granted Mrs Laybourn custody, and a divorce, at a hearing at which her husband was not represented. Mr Laybourn subsequently obtained a court order giving him access for the months of February and August until the Hague application, which is under appeal, is determined.

It is the second time Mr Laybourn alleges his ex-wife has breached the access arrangement. He cancelled a visit last August when told Mrs Laybourn had taken Dylan to a secret location.

But his custody period in February went smoothly after Turkish officials supervised the handover.