The Miami Herald reports that the luxury Epic Hotel in Miami may not be the source of the fatal strain of Legionnaires’ disease that has seen two holiday makers hospitalized and another die after staying at the hotel.

Initial reports indicated that a new water filtration system could be the cause of the outbreak which saw the hotel stop accepting guests and over 300 residents having to be moved. The system has been suspected of removing the chlorine from the water, used to prevent contamination by harmful bacteria.

It has now come to light the four other buildings in the Miami area have the same filtration system and officials are working with the owners to make sure water systems are safe.

Tests at the Epic have shown that Leigonella bacteria was present in bathroom fixtures and fittings in a high enough concentration to cause contamination but more testing is needed to determine whether the strains present are the same that struck down the tourists.

All the guests struck down by the disease were from Europe. The first to be struck down was an English tourist who stayed at the hotel in September 2009. The holiday maker intended to check-out of the hotel and board a cruise but had to be taken to hospital where it was later confirmed that he had died from Legionnaires’ disease.

Another tourist who visited the hotel in November and a woman who stayed in December 2009 were also diagnosed with having contracted the disease.

The Epic became centre of the investigation as all three victims had visited the hotel, however both the Miami-Dade County Health Department and Officials of the U.S. Centers for Disease Control and Prevention have said it is unlikely the hotel was the source after one of the Epic victims had contracted the same strain as a fourth victim who had not visited the hotel.

Further tests are due to continue but some experts have expressed the view that the source of the original contamination may never be discovered.