A pair of birds have given a north Norfolk post box a first-class stamp of approval by choosing it for their nest.

For the past three spring-times postman Lee Dyball has been finding more than letters and postcards in East Beckham's only post box when he arrives to empty it.

'It starts with a few twigs in there and then it gradually builds up,' said Mr Dyball, who has been a postman for 13 years and covers a rural round near Sheringham which includes East Beckham, Aylmerton, Felbrigg, Gresham and Lower Gresham.

He added: 'Three years ago when I looked there was also moss, and when I checked again about three weeks later there were four or five chicks in the nest.'

This year he once again alerted his bosses to the birds' arrival and a notice is now tied to the box telling the public about the squatters and asking them to post their mail elsewhere.

Mr Dyball said the post box was not used very often by the public and the nearest alternative was about two miles away in Gresham.

He believes the birds are blue tits, and a spokesman for the Thetford-based British Trust for Ornithology confirmed that this was 'quite possible'.

The spokesman said it could be the same pair returning each year, but the number of chicks Mr Dyball had spotted was small for blue tits.

'They can lay up to 11 eggs, incubate them for 14 days, and the young fledge from the nest about 14 days later,' said the spokesman.

Chicks needed to eat about 100 caterpillars each per day, which kept their parents very busy, he added.

Last year had been a particularly good breeding season for blue tits with the number of young up by 63.6pc compared to the previous five years.

Mr Dyball said he would check the post box after a few weeks and give the 'all-clear' once the nest was empty so that it could once again be used for its proper purpose.

alex.hurrell@archant.co.uk