Leading Aircraftman Ronald Maddison died at the base in 1953

The hearing into the death of 20-year-old Ronald Maddison, who died after being exposed to sarin in 1953, is now in its 12th week.

Wiltshire Coroner David Masters decided to release the jury sitting at Trowbridge to give them a break.

The inquest will resume on 23 August and is expected to run until September.

Dangerous trials

Leading Aircraftman Maddison collapsed and died within minutes of having 200mg of sarin drops put on his arm at the top secret base on Salisbury Plain.

The original inquest was held behind closed doors "for reasons of national security" but has been reopened after years of campaigning against its open verdict.

Lawyers say the outcome of the inquest could lead to legal action by Porton Down veterans who claim they were duped into taking part in similar dangerous trials.