DORSET is one of the areas most affected as a result of the NHS mislaying more than half a million pieces of confidential medical correspondence.

The documents sent between GPs and hospitals over five years, including treatment plans and cancer test results, did not reach their recipients because they were mistakenly stored in a warehouse by private company NHS Shared Business Services (SBS).

There have been allegations of a "cover up" after The Guardian reported that NHS England has been quietly reviewing how many patients had been affected by the error, which was discovered in March 2016.

According to internal NHS documents seen by the newspaper, Dorset is one of the areas with the largest number of cases of potential harm to patients, based on a clinical review already undertaken.

More than 22,000 documents went missing relating to people in both Dorset CCG and Northern, Eastern and Western Devon CCG.

The NHS is now spending millions of pounds assessing the scale of the situation and will probe whether the delays contributed to any patients' deaths.

Liberal Democrat leader Tim Farron said: "This looks, to me, like a cover up. (Health Secretary) Jeremy Hunt has serious questions to answer.

"I worry that while all this correspondence - including test results - has gathered dust, patients have been put at risk.

"People could have died as a result of this, and so we need to know who knew what and when."

Medical negligence solicitor David Simpson of Coles Miller, Poole said: “Where the data has not been delivered to clinicians, they have potentially been prevented from providing appropriate treatment.

“This has almost certainly caused avoidable harm to some, ranging from minor symptoms to quite possibly catastrophic outcomes – perhaps even fatal.

“What if a diagnosis of cancer has not been communicated to the clinicians? That cancer may have been treatable at the time but may since have spread.

“We quite commonly deal with such claims and to say that there is no evidence so far that any patients’ safety has been put at risk beggars belief.

“This is a very serious blunder and as soon as anyone learnt about it, the information should have been made public and all relevant patients and treating clinicians informed so that urgent action could have been taken as appropriate,” he added.

An NHS England spokesman said: “Some correspondence forwarded to NHS Shared Business Services between 2011-2016 was not re-directed or forwarded by them to GP surgeries or linked to the medical record when the sender sent correspondence to the wrong GP or the patient changed practice.

"A team including clinical experts has reviewed that old correspondence and it has now all been delivered wherever possible to the correct practice. SBS have expressed regret for this situation.”