Police found hundreds of rounds of ammunition and home-made explosive devices including a grenade at the Kirklees home of a defendant who has since undergone gender re-alignment surgery to become a woman.

Leeds Crown Court heard Heather Anne Exley, 45, went to Thailand for the painful surgery while on bail following the discovery at her home on April 14, 2014. She has now been jailed for three years.

Robin Frieze representing her said she had been going through the process of transitioning from a man to woman for five to six years having felt all her life she was a female trapped in a man’s body.

She was trusted on bail to return to the UK and had now undergone most of the surgery required and “can get on with her life.”

He said: “initially when all this was found there was a suspicion it was linked to terrorism.” He said the police had therefore made thorough checks and it was accepted there was no sinister or ulterior motive for the explosives and ammunition.

A box of grenades found under the bed

Exley had an interest in militaria and chemicals and made items at her home and then did not know what to do with them.

He told the court following discussions with the Home Office it was anticipated Exley would serve her jail term in New Hall prison for women at Flockton and not a male prison.

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Exley who was referred to throughout the case as Heather was previously known as John.

Michael Smith prosecuting said in 2012 officers went to Exley’s address in Penn Drive, Hightown, Liversidge to speak to her because of concerns from the Post Office about chemicals being transported through the mail.

A subsequent search of the house over several days revealed the explosive devices and substances as well as over 2,000 rounds of home loaded cartridges.

Cartridges recovered from Exley's home

Among the items found was “a hand grenade type device found in the defendant’s bedroom.” That was a viable improvised hand-made grenade consisting of 30 grammes of high explosive inside a metal canister surrounded by a black epoxy resin.”

Police also found 10 partially constructed hand grenades in her bedroom without PETN explosives in them and also 10 improvised detonators which had been modified from commercially purchased initiators with added explosives inserted.

They also found 9.8grammes of PETN, a powerful secondary explosive which if detonated by itself could cause serious if not fatal injuries but would not be subject to spontaneous combustion.

The ammunition found included one single round of .40 Smith and Wesson which had been modified with a hole drilled in the nose so it would expand on impact and 16 jacketed hollow point soft nose bullets again designed to expand on impact.

Exley admitted 10 charges of having an explosive substance, two of possessing prohibited ammunition and possessing ammunition without a firearm certificate.

Ammunition draped over a bed in Exley's home

Jailing her for three years Judge James Spencer QC said she knew what she was doing was illegal.

“I have read the report that this was something of an obsession you had and the reason ascribed to it whether over-compensation for other problems does not mitigate this.”

He said it was accepted her motives were not sinister but she could have come under pressure from others who learnt of it or it could have been stolen by others with sinister motives

“It is the potential for harm caused by the possession of such a quantity of such material. “

Pistol clips found at Exley's Liversedge home