Police are investigating the theft of items from a Royal Mail van parked in Chorley town centre.

The haul included a special delivery package containing letters to Chorley MP Lindsay Hoyle.

The unattended van was parked on the Flat Iron car park close to the Burger King restaurant, Market Walk, at 8.50am on Saturday as the driver made a delivery.

Labour MP Mr Hoyle says he is "extremely concerned" about the theft and has contacted both Royal Mail and the police about the incident.

All mail sent to the House of Commons during the summer recess is re-directed to the MP's Chorley office on the corner of Market Street and Fazakerley Street, including some from constituents, government ministers and various interest groups.

Mr Hoyle said a package is delivered each day containing on average between 20-40 letters.

"The package would have included letters from constituents and other documents which are extremely important to me but can be of no value whatsoever to the person or persons who stole the package.

"I have contacted both the Royal Mail and the police about this matter and I can only apologise now to any constituent whose letter may have been contained within this package sent from the House of Commons to my constituency office in Chorley.

"If you have written to me at the House of Commons at the end of last week please contact my office on 01257 271555 to ensure that your correspondence has arrived."

A Royal Mail spokesman said: "The mail van was broken into while the driver was making a delivery and a small number of packages were taken.

"Police are investigating and we have contacted Mr Hoyle's office and the other customers affected."

Acting detective inspector Jo South, of Chorley Police, said : "A Royal Mail van was entered on the Flat Iron car park on Saturday morning through an insecure passenger side door and a number of items were taken. We are continuing our investigations into the theft."