Police tape
Reuters

Police have arrested a US citizen for allegedly selling cyanide to Hull based Briton who committed suicide using the poisonous chemical.

US police arrested Sidney Kilmartin, 52, in Maine, New England on federal charges that he mailed potassium cyanide to Andrew Denton, 49, as well as advising him how to take it.

Denton was found dead in Holland Street in December 2012.

UK's Humberside Police passed over the case to the US Postal Inspection Service.

"In my 28 years as an inspector I have never come across potassium cyanide being mailed and it is even rarer that it has led to a homicide," said Postal Inspector Michael Desrosiers when he travelled to Hull to gather evidence from witnesses in June 2014.

Humberside Police also claim that Kilmartin used a pseudonym when he facilitated the sale of cyanide to Denton.