A gamekeeper sparked a major health scare and forced the closure of part of a city after claiming he ate cyanide in a bid to die "in a blaze of glory".

A housing estate was cordoned off for several hours over fears that the cyanide Graeme Thompson said he swallowed could kill hundreds of residents living nearby.

Dozens of emergency service workers cut off an area around Thompson's Perth home because of the ultra-lethal nature of the poison involved.

The 29-year-old called 999 and said he had swallowed a packet of razor blades and a "golf ball sized" packet of Cymag, a cyanide-based pest killer which has been outlawed in the UK for several years.

The chemical is so strong that it can seep through the skin of anyone who ingests it and pollute the air so quickly that anyone else standing nearby is likely to die.

The large-scale operation to isolate the gamekeeper involved six police vehicles, 14 police officers, eight ambulances, seven paramedics and seven specialist medics.

Thompson, of Primrose Crescent, Perth, admitted depriving the public of emergency service workers by making false claims he swallowed razor blades and cyanide on November 23 last year. He also admitted blocking the streets as a consequence.

When Cymag comes into contact with moisture it produces hydrogen cyanide gas and would be fatal in seconds. It can also be released through the pores of anyone who has ingested it.

Thompson stated this was to kill himself when the razor blades burst the bag in his stomach so the poison entered his system. He gave the officers a suicide note and said he wanted to go out in a blaze of glory.

"The officers contacted control and were told they may have been contaminated with cyanide so they should not return. They were effectively quarantined to prevent contaminating others.

The officers with the accused were advised to stay as far as possible from him to avoid his bodily fluids getting on them."However, the officers had to tackle Thompson several times as he tried to leave and were still in his garden when he began spitting on the ground beside them."

He appeared to be relishing the attention he was attracting and the alarm he was causing."

Every officer in Perth was called to deal with the crisis situation and other officers were called in from rural towns to man the main Tayside Police Western Division HQ.

Thompson and the officers were eventually transported to Ninewells Hospital in Dundee under an escort and they were taken to the decontamination unit for tests.

Solicitor Ken Dalling, defending, said: "It is natural in the way of human relations to want to be the centre of attention. He would not have gone out in a blaze of glory.

"He accepts he was seeking attention. He was looking for one ambulance, not the multiple vehicles which turned up. It was very far from him being a walking biohazard. If he had actually done what he didn't do then the effect would have been instantaneous total system failure.

"He is very sorry for the trouble he caused and had no intention of alarming anyone or causing the disruption that he did. He had a failed relationship. He was not able to cope with the emotions generated by that failure."

Thompson was remanded in custody pending sentence and the case was continued for the preparation of social work reports.