Nine British holidaymakers have been struck down with Legionnaire's disease after holidaying at the same hotel in Spain.
One 76-year-old man is in intensive care at the Benidorm Clinic, where three other Britons have been treated.
Five other tourists, who arrived home before symptoms started, have been treated for the disease in the UK.
Legionnaire's disease is caused by infected water droplets, and symptoms include shortness of breath, headaches, coughing, pain, and muscle aches.
All nine holidaymakers had been staying at the four-star Diamante Beach Hotel in Calpe on Spain's Costa Blanca, and were travelling with Saga.
A Saga spokesman said the firm had contacted everyone who had at the hotel through them in the past month, had moved customers to a new hotel, and had sent in scientists in an attempt to find the source of the outbreak, to no avail.
Dr Delfin Arzua, from the Benidorm Clinic, told the Express: "Four British holidaymakers were admitted with symptoms of pneumonia and tests have confirmed legionnaires' disease."
And a spokeswoman for the regional health authority said: "As the incubation period is 10 to 12 days,we cannot rule out new cases."
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