The bodies of Neil Moon, 49, from Spalding, and 34-year-old Jonathan 'Jon' Collins, from Watton, were discovered at Banham Poultry in Attleborough in October 2018.

Both suffocated following a build up of nitrogen in a narrow passageway at the side of the factory that they had entered as part of their work to eradicate rodents.

A coroner's court review in 2024 was told the pair were found with frozen hands and faces and there was evidence of frost on the floor, but mystery had shrouded exactly how they had died, as no full inquest of court proceedings had been held.

Police at Banham Poultry, next to the Attleborough railway station, after two pest controllers were found dead (Image: Newsquest)

Neil Moon died from asphyxiation after a gas leak (Image: Norfolk Constabulary)

But more details emerged at Norwich Crown Court this week, where two companies are being sentenced over health and safety breaches.

The hearing was told the leak was the result of a poorly installed duct meant to carry the gases to a chimney on the factory roof becoming detached causing it to fall into the passageway.

Banham Poultry Limited and Air Products plc have both pleaded guilty pleas to the health and safety offences on the basis that the “breaches were causative of the deaths of Mr Moon and Mr Collins”.

Craig Hassall KC, prosecuting, said nitrogen gas used to chill slaughtered chickens had pooled in the passage after being expelled from a safe chill system that had been designed, installed and maintained by Air Products.

He said: “When these men entered the passageway ducting had become detached, pumping concentrated nitrogen into a narrow space.

“Ultimately, they were killed by a colourless, odourless gas. When they walked into the passageway they were given no warning of the risks.”

COMPANIES 'CAVILIER' WITH SAFETY

The court was told the two workers employed by pest control contractors Ecolab had arrived at the factory at 8.30am and were last known to be alive at 11.40am when captured on CCTV.

But when neither of the men returned home that evening their worried families raised concerns, sparking a search of the site.

Their bodies were discovered at 1am in a one-man width passageway running between the factory and the tracks at Attleborough railway station.

Jonathan (Jon) Collins had been working as a pest controller when he died (Image: Norfolk Constabulary)

Mr Hassall told the sentencing hearing that the safe chill system had been installed at the factory in May 2017.

However, concerns had subsequently been raised about clouds of mist drifting across the railway station tracks and platforms.

To try to solve the problem three modifications were made in September 2017, January 2018 and April 2018 including adding extra exhaust ducts to allow the waste gas be expelled from the roof chimney.

Mr Hassell said: “The prosecution case is that additions and communications about these changes were not properly done and the ducting added to the chimney was not properly robust.”

He said the actions of the two companies had been "cavalier" and they had failed to keep employees and others working on site safe.

The families of the two men reported them missing when they failed the return home (Image: Newsquest)

The bodies of the two men were found in a passageway between the factory and the track at Attleborough rail station (Image: Newsquest)

The prosecutor said safety systems at the factory had been lax with no record of Mr Moon being on site or Mr Collins, who had signed in, having left.

Banham Poultry Limited, which had employed 900 people, entered administration in 2018 and is currently in liquidation.

Mr Hassell said financial problems had delayed plans to relocate the safe chill system on the factory site.

'THEY WERE ROBBED OF THEIR LIVES'

At the packed sentencing hearing, due to last two days, families of the two men read emotional statements in tribute.

Mr Moon’s wife Gillian, who was pregnant at the time, said her husband had been a “calm and easy-going person” who was someone who would “do anything for anyone”.

She said: "My life stopped but I had to find the strength to carry on for our son.”

She added: “I still don’t know why it has taken these companies seven a half years to accept responsibility for causing these deaths.

“The careless and reckless actions of those responsible have had catastrophic consequences.”

His daughter Dakota described him as an “amazing father”.

She added: “My dad was a kind and caring man just doing his job. They were robbed of their lives.”

Banham Poultry and Air Products both pleaded guilty to the health and safety offence (Image: Newsquest)

Banham Poultry entered administration in 2018 and no longer operates the factory (Image: Newsquest)

Mr Collins' fiancée Sara Dutton said he was a “strong and devoted family man” who doted on his children aged one, four and six at the time of his death.

She said he had been excited to start a new job with future plans for a new home and to get married.

“My life and the lives of my children changed forever,” she added.

“Our grief has not diminished over time. I have had seven years just treading water. Not really living, just waiting for the truth.”

The hearing continues.

© Eastern Daily Press