A failing hospital trust spent £4million employing temporary A&E staff.
Barking, Havering and Redbridge NHS Trust (BHRUT) spent nearly three times the average for London hospitals on agency workers to deal with staff shortages, figures reveal.
The trust, which runs King George Hospital in Goodmayes, was placed in special measures by the Care Quality Commission last month.
Inspectors found unsafe care in A&E departments at both King George and Queen's Hospital in Romford due to a lack of full-time staff, as well as long waiting times.
A&E services at King George Hospital have been earmarked for closure in 2015, when services are expected to move to Queen's Hospital.
A spokesperson for BHRUT clinical commissioning groups said: “The current situation where two A&Es are being run separately but geographically close to each other results in staff and services being spread too thinly across both sites and Queen’s A&E isn’t designed for the number of patients being seen.
“BHRUT is working to recruit more senior doctors and redesign Queen’s A&E to enable more patients to be seen in a safer environment.
“In addition the urgent care centres at both sites will be enhanced so they are more effective and can see a wider range of patients.
“Out of hospital services will be developed improving access to GPs and better community services closer to patient’s homes. Increasingly seven day running of all services will be what patients can expect.”