Royal Mail has launched an investigation after “hundreds” of undelivered letters were “discarded” on a country road.

The SDLP MLA, Mark H Durkan, said an estimated 400 unopened letters were handed in to his office after being found “dumped” in the Mobuoy area, outside Londonderry, on Wednesday.

Many were bundled together with elastic bands and included correspondence from health trusts and banks to addresses in the Derry area.

The police said follow-up inquiries led to the “discovery and seizure” of a further quantity of mail.

“Our teams will work to recover and process the items so they can be returned to the postal network and delivered to customers,” a Royal Mail spokesperson said.

Durkan described the discovery of large amounts of personal mail dumped in the countryside as “absolutely shocking”.

“Multiple bags of undelivered mail have been discovered dumped on a country road,” he said.

“It is my understanding that there were other similar bags strewn around the area.

“There must be a full investigation into this appalling situation, proper accountability.”

Durkan said many of the letters appear to have been sent by health trusts, government departments and banks, and are likely to contain confidential, sensitive information.

He now fears some people may have missed important correspondence, potentially affecting their access to essential services.

In a statement, the Police Service of Northern Ireland (PSNI) said they received a report on Wednesday “in relation to the discovery of postal mail at a location in the area of Mobuoy Road”.

“Follow-up enquiries by police led to the subsequent discovery and seizure of a further quantity of mail.

“Police enquiries are ongoing, and officers are liaising with Royal Mail in respect of the matter.”