London, Oct 15 (IANS): A British minister had to apologise after being caught dumping official documents, some of them even related to terrorism, in a park rubbish bin.

Cabinet Office minister Oliver Letwin, who is also the senior policy adviser to Prime Minister David Cameron, was ­photographed on five occasions tipping ­letters and other paperwork into public waste bins in London's St James's Park, the Daily Express reported.

Some of the documents, which he tore up but did not shred, related to national security, although his aides insisted none of it was ­classified or secret material.

Much of the paperwork included correspondence from members of the public in Letwin's West Dorset constituency, raising local concerns and personal matters with many private addresses and phone numbers clearly legible.

Over a hundred discarded documents were found in bins, including five Intelligence and Security Committee letters.

Letwin, considered a mildly eccentric figure in Whitehall, but is highly regarded by Cameron for his policy advice, admitted to working in the park on some mornings rather than in his Whitehall office and disposing of some papers in bins after reading them.

He said: "I was walking around dictating responses and I did not want the paper to weigh me down.

"I apologise to constituents who wrote to me because on reflection I should not have disposed of them in that way.

"I apologise to those who were affected and I can understand their feelings."