Kalvin Paul Chapman took a fatal overdose of a substance that is used to kill death row prisoners at his flat in Manchester.
The 43-year-old bought it while on holiday after having been diagnosed with a cancerous tumour behind his eye and smuggled the drug, which is illegal in the UK, back to Britain.
On the night of his death, he emailed Greater Manchester Police to request they collect his body.
'It will probably kill me in 20 minutes,' he wrote. 'Can you please send someone to pick up my body. My flat door is unlocked. Much appreciated.'