A survey of house prices in a national park has found that prices have risen by an average of £80,000 in just a year.

But officers at the North York Moors National Park Authority have put the huge increase down to a high number of larger than average properties being on the market when the survey was carried out.

A number of the properties had swimming pools, land, stables and holiday cottages, which experts say has distorted the average figure.

The survey, carried out from June 14 to 18, found three properties valued at more than £1m and six at more than £800,000.

The survey also found that there had been a drop in the number of properties on the market since 2000, with just 128 being up for sale.

Planning officer Judith Ferrier said: "Of these 128 properties for sale this year, only one was valued under £100,000. This helps illustrate the problem faced by many local people who are unable to afford market housing in the national park, particularly those wishing to get a first step on the property ladder."

The authority's planning committee will consider the survey on Thursday.