Chief Constable George Hamilton
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Stakeknife: Chief constable says investigation will examine 'controversial cases'

An investigation into the alleged activities of the Army's most high-ranking agent in the IRA will also examine possible crimes by IRA members, agents, Army and police handlers.

The agent, codenamed Stakeknife, has been linked to more than 50 murders.

Chief Constable George Hamilton said the investigation would examine a series of highly "controversial" cases stretching over a number of years.