Levels of Legionella contamination at the Institute for Animal Health (IAH) at Pirbright, Surrey have been classed as "insignificant", the institute said last night.
In a statement, Dr John Anderson, head of laboratory at the IAH, said the investigation into the suspected case of Legionella contamination had been a "regrettable distraction" for scientists there, with levels "so low that the [British] Health and Safety Executive require no further action".
British authorities have previously said there is a "strong possibility" that the IAH and the private Merial pharmaceutical laboratory are the source of the foot-and-mouth disease (FMD) outbreak in the Surrey area. The two laboratories share the same site at Pirbright.
"The IAH has been aware of allegations made today of Legionella contamination at our laboratory at Pirbright," Dr Anderson said last night.
"The results obtained this evening from the Health Protection Agency (HPA) show . . . such a low level that it is on the threshold of detection and could be considered background level. This level is so low that the HSE requires no further action, other than maintaining our current monitoring regime. However, we have taken positive action and have taken the relevant water system out of use and this is being disinfected."
Dr Anderson's comments followed confirmation earlier yesterday that the HPA was investigating a reported case of Legionnaires' disease with "alleged links" to the IAH.
Legionnaires' disease is caused by a type of bacterium which can cause serious illness if inhaled. It is carried by water, for example in showers or spas. It cannot be spread from one person to another.
As of yesterday evening, a total of 576 animals, including cattle, pigs, sheep and goats, had been slaughtered in Britain since the FMD outbreak began. However, the results of tests on a suspected third case of foot-and-mouth disease at a farm within a 10km surveillance zone are not yet available. The culling of 362 animals on this third site, which is adjacent to one of the previously infected premises, was completed yesterday.
The Minister for Agriculture and Food, Mary Coughlan, yesterday said that a positive result from samples on the third farm would have no "significant implications", given its location within one of the existing protection zones.
Farm leaders North and South yesterday called on their respective Ministers for Agriculture to ban the importation of beef from Brazil because of the dangers it posed to the European beef industry.
The Irish Farmers' Association president, Padraig Walshe, held a joint press conference with Ulster Farmers' Union president Kenneth Sharkey yesterday in Dublin.
Mr Walshe said the treatment of beef from Britain by the EU was in sharp contrast with that given to beef being imported every day from Brazil where there were multiple cases of foot-and-mouth disease every day.
Mr Sharkey added that he would be asking the Minister for Agriculture in Northern Ireland, Michelle Gildernew, to put pressure on the EU Commission to impose a ban.
Ms Coughlan said she was satisfied with the controls put in place since the outbreak. She said it would be August 25th next before there would be any scaling down of the controls in Britain, presuming there were no further outbreaks.
"If there was another outbreak you would have to add another 14 days from August 25th," she said.