A spokesman for the holiday village, which last month won gold in the David Bellamy conservation awards, said: ?The Secret World has hand-reared them (the squirrels) for more than four months, feeding them a special type of milk, before deciding they were strong enough to be returned to the wild.?

The wildlife charity claimed it has a special licence to release the animals, but Natural England (NE) has yet to confirm this.

An NE spokesman said: ?The licensing team has confirmed that we have on record a licence for Secret World to keep grey squirrels. However, there is no record of this licence extending to the re-release of grey squirrels. Our wildlife licensing unit is currently looking into this incident, but has yet to confirm whether it was permitted to release them.?

In 2009, Natural England issued seven licences to re-release ?rehabilitated? grey squirrels and one licence for the capture and release of grey squirrels for scientific research.