On Tuesday, 2 February, Frank Sonny Redman, 34 was located and arrested at an address in Uxbridge on suspicion of assisting a suicide (Suicide Act 1961).
He remains in custody at a west London police station.
Earlier on 2 February, a 34-year old woman was arrested in Ruislip on suspicion of assisting an offender. She also remains in police custody.
At 5.35pm on Sunday, 31 January, police were called to a residential address on Collingwood Road in Uxbridge following reports of a man taken unwell.
Officers and the London Ambulance Service attended. The 60-year-old man was pronounced dead at the scene.
Enquiries continue to establish the full circumstances. A post-mortem examination held on 1 February was inconclusive and officers await the results of further tests.
While the cause of his death is yet to be confirmed, the circumstances are being investigated by detectives from the West Area Command Unit.