The British government launched a covert operation in support of the Nepali government against communist rebels during the country's decadelong Maoist insurgency, according to a new book, entitled Kathmandu.

The book, unveiled officially on Sept 4, says British authorities had funded and also conducted a four-year intelligence operation in the Himalayan country from 2002 to 2006 code-named "Operation Mustang".

The book, which is on sale in Nepal and neighboring India, claims that the covert operation - conducted by spy agency MI6 - was specially focused on supporting Nepal's state security agency, the Nepal Army, in the fight against Maoist insurgents, leading to their murder, arrest and torture.