Detained British academic Lesley McCulloch and American Joy Lee Sadler are "private intelligence" agents determined to see Aceh split from Indonesia, Jakarta intelligence sources say.

The pair were detained September 10 emerging from what authorities say is a known concentration of support for the Free Aceh Movement (GAM) in Tapak Tuan regency, South Aceh.

They are accused of having carried photographs and documents that strongly suggest contact with GAM, and of having abused their tourist visas.

Indonesian authorities were threatening to take the pair to court over their alleged immigration violations, rather than deport them as originally planned.

"Tapak Tuan regency is not a popular destination. It is a base of GAM activities and life is very tense there," says a source in the region's police headquarters.

McCulloch, in a note smuggled out to The Guardian after the pair were finally able to meet a lawyer, said they were detained by an army patrol that stopped the bus they were on with their guide. Soldiers immediately started threatening them. "This soldier held a knife to my throat and screamed at the top of his voice he was going to kill me."

McCulloch said she and Ms Sadler were beaten by soldiers at the remote base at Keunde Rundeng where they were held on the first night. "The commander punched Joy in the stomach and one of his men hit me," she said.

Handed over to South Aceh police on September 11, they were detained there until September 15, then transferred to Medan in a process that left their whereabouts unknown for 36 hours. The pair were later transferred to provincial capital Banda Aceh.

McCulloch, in a phone interview from a bathroom at Aceh police headquarters, told Radio Australia it was not true the pair were carrying GAM documents.

"They found no documentation on us. They say that they found GAM documents, that's not true. They found some handwritten statements that I'd taken from victims and people whose houses had been burnt, who'd been beaten, whose relatives had been shot, had disappeared etc. But that's all. There are no official GAM documents."

McCulloch added that she and Sadler had been charged with abusing their visas and that Sadler was likely to be released first.

"They say for me it's a bad situation, because they suspect me of espionage or something similar."

"They have no proof of anything, they're very suspicious but there's no evidence to link me to anything. So I'm hoping that with the lawyers and the statements that we've made, and with the pressure in Jakarta with the embassies, that we can get this process finished with as quickly as possible."

In Australia, the minority Greens Party protested the detentions, adding that it had moved to support independence for Aceh.

The detention of the two women provoked strong protests from their embassies when access was denied for some days after their arrest. There were allegations that the women had been beaten.

"We conduct searches of the area at least five times a day, and so do the GAM people," says the police source. "Why, suddenly, do two foreigners who have never been here before go to a place like that. And our strongest suspicious is they are independent intelligence"

Police say video footage carried by the pair shows GAM activities that are not the normal course of action for the movement. "We presume that these exhibitions were mounted for the benefit of the foreign guests," says the police source.

McCulloch has worked as a member of staff of the University of Tasmania while Sadler is a nurse pursuing humanitarian work in the area.

A senior member of the Indonesian intelligence community with close links to the office of the Coordinating Ministry of Security and Defense says he also believes that the pair were operating as agencts for a fifth column of anti-Indonesian NGOs.

He says he received calls Friday from British intelligence and other European intelligence officials offering assistance for the detained pair to leave Indonesia.

"Of course I refused as I have data that identifies who they are," he says. The source alleges that McCulloch works for a private intelligence office, under the cover of the Henry Dunant Centre. "I will unveil all the data later," he says.

Indonesian officials earlier insinuated that the Henry Dunant Centre was biased toward GAM, a charge immediately refuted by the agency, which has been brokering the series of talks between Indonesia and GAM. A new round was scheduled for early October before the detentions of the pair.

Another source in the Indonesian intelligence community who works with the Military says Britain is well aware of Indonesia's problems with Aceh, and therefore why the two women were there.

"Of course they will say they were scientists doing reseach in a certain part of this country. Usually intelligence operatives work undercover, for instance as a journalist, NGO worker or researcher."

The Indonesian reaction to the visit of the two foreigners to the GAM base serves to reinforce growing paranoia within the intelligence community over the work of NGOs in Indonesia. While some are above board, Indonesian authorities suspect others are pursuing their own political agendas.

Adding fuel to Indonesia's arguments of an NGO alliance to break up the country, the executive director of Australia's Institute of Public Affairs (IPA), Dr. Mike Nahan, said Friday that a number of organizations in Australia have given their support to separatism in Indonesia, particularly in Papua, Antara reported.

Nahan acknowledged that the NGOs receive funds from the Australian government, but said these fuinds were not used to support separatism.

It was quite different if the NGOs should procure funds from the Australian government to finance social projects, then used these funds to finance support for secessionist movements.

He pinpointed the Australian People Health, Education and Development Aid (APHEDA) organization, affiliated with the Australian trade union movement, as one body which received Australian government funds and had actively supported independence for East Timor and had now turned its attention to Papua.

Between 1999-2000, APHEDA operations in Indonesia had been funded with A$4.4 million in government funds.

Army Chief Gen. Ryamizard Ryacudu said the case of the Aceh pair had prompted the authorities to take a harder line against foreigners in conflict regions, strengthening fears that the government wants to close off Aceh, Papua and Maluku to foreigners, whether they be NGO workers, researchers, or journalists.