The Legionella bug contaminates water supplies and can be fatal

He was diagnosed with the illness on Wednesday after being in hospital with suspected bronchial pneumonia for over a week.

The Health and Safety Executive is carrying out checks at the BAe Systems Royal Ordnance site in Birtley.

The shell plant where the man works has been closed while checks are made but the rest of the site remains open.

Safety of workforce

Company spokeswoman Marilyn Swann said no other staff members are thought to have the disease, but the safety of the workforce came first.

She said: "No other workers have the same symptoms as he has but if anybody is worried they can talk to our local occupation health people, even if they just want to talk about what the illness is.

"Legionnaires' disease cannot be transferred from person to person, it is something that is transmitted through the air so it is the case that you have to be in that environment and not someone breathing on you."

In 2002, seven people died from the disease in Cumbria in what was described as the country's worst outbreak.