One patient lay dead for up to four-and-a-half hours before being discovered while another died unexpectedly because of staff shortages at one of London’s busiest A&Es.

A report into the crisis-hit North Middlesex hospital today revealed further details about failures in care that has resulted in its urgent and emergency services being declared “inadequate”.

The hospital, in Edmonton, revealed chief executive Julie Lowe was “on leave”. It is understood she will not be returning to her £160,000-a-year post.

The Care Quality Commission, whose inspectors returned to North Middlesex in May and June after concerns were sparked about a number of serious incidents, was told that an internal investigation had found that the failure of doctors to undertake hourly rounds “meant that a patient had lain dead for up to four-and-a-half hours before being found”.

In another case, an investigation into an unexpected death found that the A&E department was “two to three nurses and one middle grade doctor short on the day in question”.

Today’s report makes clear that the December 2013 closure of the A&E department at Chase Farm hospital, Enfield, had a “significant impact on the demand for services at North Middlesex”, with about 500 A&E attendances a day.

It said there were “excessive” delays in patients seeing a doctor, other departments were “not supportive” of emergency staff and there was an “overbearing” trust management.

The CQC said the hospital had “turned a corner” since a visit in April but warned further improvements were needed by August 26. Another inspection will take place in September.

North Middlesex medical director Dr Cathy Cale said: “We are extremely sorry for the current problems in A&E and for the long waiting times for some patients. We are committed to getting back to the standards that we and our patients expect.”