A specialist police unit that investigates killings from the Troubles in Northern Ireland is to be closed down due to budget cuts, the PSNI has announced.

The Historical Enquiries Team (HET) was set up in 2005 to review more than 3,000 unsolved deaths during the conflict.

The unit was subject to a highly critical inspectors' report last year that questioned whether it investigated state killings with the same rigour as those committed by paramilitaries.

The PSNI decision comes after Stormont's Department of Justice asked it to make a £50 million in-year budget cut.

Police said it was anticipated the HET would be replaced by a "much smaller" PSNI branch that would focus on legacy investigations.

A number of temporary agency workers, many of them retired police officers, are involved in HET investigations.

Police said closing the HET was a consequence of its decision not to extend a contract with the Grafton Recruitment employment agency beyond the end of the year.

That will see more than 300 agency staff not have their contracts renewed into 2015.

PSNI Assistant Chief Constable Alistair Finlay said: "Today's news will have an impact on a large number of people.

"With cuts of this magnitude, as a police service, our immediate obligations must be towards keeping people safe today.

"The loss of these posts by the end of the year will effectively mean the closure of HET."

The PSNI has an annual budget of around £1.2 billion, but more than a third of that is fixed costs, such as pensions.

The service's operating budget of £740 million for this year was already down £47 million on 2013/14, before it was asked to make the further £50 million reduction.