Sending three Chinook helicopters from RAF Brize Norton to Nepal, where they were denied entry, cost £1m, it has been reported.

The helicopters were dispatched last month to help with relief efforts after two earthquakes left thousands dead.

But they were stranded in India for almost a month because the Nepalese government feared that they would cause damage to already fragile houses.

It is understood the crews returned to the UK on Thursday after the failed mission cost the taxpayer £1m.