Doctors could have done nothing to save a man who committed suicide with a rarely used poison, a coroner has ruled.

20-year-old farmer Samuel Warden rang 999 after deliberately swallowing a poison normally used to kill rabbits at his home in Heatherwood Close, Kingswood, on May 29 last year.

A hearing in County Hall, Maidstone, on Thursday, October 4, heard no one else was in the house at the time and that a suicide note had later been found.

It was only the second known case of such poisoning in the UK in fifteen years, and doctors had to carry out research on the poison as they awaited Mr Warden's arrival at Maidstone Hospital.

Despite their best efforts he died in the intensive care unit at 4.30am the following morning.

DC Simon Powell said investigations revealed Mr Warden had conducted internet searches, the afternoon before his death, on the dangers of the poison - which releases a toxic gas on contact with liquid and for which there is no antidote.

Mid Kent Coroner Roger Sykes said: "I am satisfied that by the time of his arrival (at hospital) his condition was irreversible."

And he added: "I am satisfied that when Sam ingested the tablet he did so deliberately."

Mr Warden had updated his facebook site at about the time he took the poison, writing "Will be feeling better soon, love you all."

The coroner recorded a verdict of suicide.