A suspected case of Legionnaires' disease in Wales could be connected to an outbreak that has killed two pensioners in England.

A 72-year-old man being treated for the disease at a Welsh hospital made two recent visits to Hereford, where five people have contracted the illness. A man and a woman in their seventies have died and three middle-aged people are being treated in Hereford County Hospital, two of them in intensive care.

Professor Rod Griffiths, director of public health for the West Midlands, said: "There is a suspected case in Wales that might be connected to the Hereford outbreak and we are investigating. That is quite helpful, because this man had only been to Hereford for a couple of short trips, so it could help us to narrow down the search for the source."

Professor Griffiths said three or four other people were being treated for suspected Legionnaires' disease across the country, but none had been near Hereford and were not believed to be connected with the outbreak.

Air conditioning systems and water cooling towers in Hereford are being checked for the legionella bacteria, which is spread in water droplets. The search is likely to continue for a few days, but the Health Protection Agency (HPA) said it was possible the source would not be found.

GPs across the region have been alerted to the symptoms of the disease, which include a flu-like illness with muscle aches, tiredness, headache, dry cough and fever.

Samples have been taken from the confirmed cases to see whether patients caught the disease from the same source. Results are expected early next week.

Dr David Kirrage, consultant in communicable diseases for the HPA, said: "We have five confirmed cases and another case in another part of the country which we are investigating."