The gun used in the murder of two unarmed police officers in Manchester on Tuesday may have come from a collection of firearms smuggled to Britain from the United States, The Times reports.
Police are now investigating whether the weapon recovered from the scene of the murders of PCs Fiona Bone and Nicola Hughes was one trafficked by Steven Greenoe.
Officers nationwide have offered cover to colleagues in Greater Manchester Police so they can attend the funerals of the two killed PCs.
Manchester's police chief said he expected "developments" in the next 24 hours over possible charges relating to the deaths of two officers.
Over 50,000 tributes have been posted to Greater Manchester Police's online book of condolence to the two killed officers and Facebook page.