Problems with the fire and electrical systems have been found at a new hospital which has been lying empty due to safety concerns.

The Royal Hospital for Children and Young People (RHCYP) in Edinburgh was due to open in July but this has been delayed until next autumn.

The opening of the flagship building was postponed just days before it was due to start treating patients after final checks revealed the critical care department's ventilation system did not meet national standards.

The delay is expected to come at an additional estimated cost of £16m as a result of work required on the site to address the issues raised, as well as continued operation and improvements.

A new report has now found work is also needed on the fire and electrical systems prior to patients moving in.

However, this is not expected to affect the current timetable which should see the Department of Clinical Neurosciences (DCN) moving to the new site in spring, followed by the rest of the children's hospital in autumn.

The National Services Scotland (NSS) review found major problems with the electricity systems, including a need for mitigation to avoid the failure of the single electrical supply to critical equipment such as life support systems.

The review found there appeared to be a "lack of qualified and experienced", authorised and competent persons for the electrical installation.

Issues were also identified with the fire system, including a requirement to upgrade fire doors and improve smoke dampers on evacuation routes.

Some compliance records could not be found and for both NHS Lothian and the consortium behind the building IHSL, the investigators said there appeared to be omissions in an effective management structure.

The report is the final part of the NSS review after the first phase last month found a range of issues, including with ventilation and water systems.

NHS Lothian chief executive Tim Davison said: "We are pleased there are no new substantive compliance issues here that may affect the timeline.

"The ventilation system in critical care remains the main issue and we continue to work through the remaining remedial works to ensure DCN can move in in the spring.

"We are also carefully risk-assessing possible further enhancements that can be achieved without affecting the current timeline."

Health Secretary Jeane Freeman said: "The safety and wellbeing of all patients and their families has always been and will remain top priority, and I am truly sorry for any impact the current situation has had on them.

"This second report from NSS has identified remedial and improvement work required within the fire and electrical systems and that will be factored into a wider plan of work being taken forward to ensure safety at the RHCYP and DCN.

"As I set out in Parliament last month, I expect the DCN to move in spring 2020, with the rest of the children's hospital migrating to the new site in autumn next year."

Both Ms Freeman and Mr Davidson praised the staff for continuing to provide high quality care in "disappointing" circumstances.