Launched in 2002, “Operation Mustang” targeted Maoist guerillas and saw British intelligence agency MI6 fund safe houses and provide training in surveillance and counter-insurgency tactics to Nepal’s army and spy agency, the National Investigation Department (NID), writer Thomas Bell told AFP Saturday.

Nepal’s decade-long civil war left more than 16,000 dead, with rebels and security forces accused of serious human rights violations including killings, rapes, torture and disappearances.

“According to senior Nepalese intelligence and army officials involved in the operation, British aid greatly strengthened their performance and led to about 100 arrests,” said Bell, whose book “Kathmandu” hits stores in South Asia on Thursday.

“It’s difficult to put an exact number on it, but certainly some of those who were arrested were tortured and disappeared,” he said.

Maoist commander Sadhuram Devkota, known by his nom-de-guerre “Prashant”, was among those captured during “Operation Mustang” in November 2004. Six weeks later, he was found hanging from a low window in his cell, with officials saying he had committed suicide.

Despite protests, no independent investigation was ever carried out.

British authorities helped construct a bug-proof building in the NID headquarters, created a secure radio network for communications and supplied everything from cameras to computers to mobile phones and night vision binoculars, according to Bell’s sources in the Nepalese security establishment. “The agency also sent a small number of British officers to Nepal, around four or five — some tied to the embassy, others operating separately,” Bell said. The officers gave the Nepalese training in how to place bugs, how to penetrate rebel networks and how to groom informers.

Bell spent about a year interviewing some 20 highly-placed sources to corroborate the details of the operation, and said a senior western official told him the operation was cleared by Britain’s Foreign Office.

A Foreign Office spokeswoman told AFP: “We do not comment on intelligence matters but, as we have repeatedly made clear, the UK does not participate in, solicit, encourage or condone the use of torture or cruel, inhuman and degrading treatment or punishment.“ In no circumstances will UK personnel ever be authorised to take such action; we neither condone such activity, nor do we ask others to do it on our behalf. “We would never authorise any action in the knowledge or belief that torture would take place at the hands of a third party.”

A Nepalese general with close knowledge of the operation told the writer there was no doubt that British authorities realised that some of the arrested suspects would be tortured and killed.

“Being British they must have thought about human rights also, but they knew exactly what was happening to them,” the general said. “The thing must have been approved at a high level.”

Bell said it was “a peculiar contradiction that while calling for an end to abuses... the British were secretly giving very significant help in arresting targets whom they knew were very likely to be tortured”. The British-born writer covered Nepal’s civil war from 2002 to 2007, reporting for The Economist and the South China Morning Post before moving to Bangkok for a two-year stint as The Daily Telegraph’s Southeast Asia correspondent.

Tejshree Thapa, senior researcher at the Asia division of Human Rights Watch, said: “Nepal’s army was known by 2002 to be an abusive force, responsible for... summary executions, torture, custodial detentions”. “To support such an army is tantamount to entrenching and encouraging abuse and impunity,” Thapa told AFP.

Nepal army spokesman Jagdish Chandra Pokharel denied all knowledge of the operation, which apparently continued even after a coup in February 2005 by the then-king Gyanendra seizing direct control prompted the British to publicly suspend all military aid to the country.

“I have no idea about MI6 training the Nepal army or any Operation Mustang,” Pokharel told AFP. Nepal is in the process of drafting a new constitution, a key step in a stalled peace process begun after the end of the civil war in 2006.