The Vatican has rejected claims that it is helping Croatia's most wanted war crimes suspect evade capture.
Many in Croatia regard Gen Ante Gotovina as a national hero
Top UN prosecutor Carla del Ponte has alleged requests for help to find Gen Ante Gotovina - believed hidden in a monastery - have met a wall of silence.
The Vatican has countered by saying Ms del Ponte has not yet responded to its requests for more details on his likely whereabouts in Croatia.
A spokesman for the Croatian Catholic Church has denied helping him.
The general, charged with the deaths of 150 Serb civilians in 1995, has been on the run for the past four years.
Ms del Ponte has repeatedly accused the Croatian authorities of not doing enough to find him, the BBC's south-east Europe analyst Gabriel Partos says.
But this is the first time she has publicly criticised the Vatican for its alleged failure to co-operate, our correspondent adds.
Ms del Ponte's spokeswoman told the BBC News website that the Vatican had refused to help in the search for him, despite being in a position to do so.
Ms del Ponte wants the authorities to act against war criminals
Ms del Ponte said Archbishop Giovanni Lajolo, responsible for the city-state's foreign relations, told her in July that the Vatican had no obligation to assist the UN's war crimes tribunal in the Hague.
Chief Vatican spokesman Joaquin Navarro-Valls confirmed that this was the case.
But he added that Ms del Ponte had not yet responded to requests for more precise information about where Gen Gotovina might have taken refuge.
Tribunal officials have told the BBC that if they had such detailed information they would not have needed the Vatican's help but instead would have asked the Croatian police to arrest him.
Ms del Ponte wrote to Pope Benedict XVI in July this year in an effort to secure the Vatican's co-operation, her spokeswoman Florence Hartmann told the BBC News website.
The Pope has yet to reply to the prosecutor's request for a meeting, Ms Hartmann said.
"The law applies to everyone, including the Vatican," she added.
The Croatian Bishops' Conference, which heads the Croatian Roman Catholic Church, dismissed Ms del Ponte's allegations.
Its spokesman Antun Suljic said the conference "has no knowledge or indications of the whereabouts" of Gen Gotovina.
Earlier this year, the European Union cited Zagreb's failure to arrest him as the reason behind delaying talks on Croatia's entry into the bloc.
Croatian authorities have insisted they are doing everything in their power to deliver him to the Hague.
Forces under Gen Gotovina's command are accused of killing scores of Serbs and expelling up to 200,000 from the Krajina region, now part of Croatia.
Many in Croatia regard him as a national hero.