The coffee served in the private offices of European Commissioners tasted decidedly odd, even though the espresso machines cost more than €6,000 (£5,150) each.

The metallic tang was too much for one eurocrat, who sent samples from his machine back to his native Austria for testing – only to receive results suggesting that the European Union’s most senior figures were being slowly poisoned. Now the Commission’s entire collection of elegant Cimbali coffee-mak-ers, together worth €120,000, have been mothballed while the Italian company – which disputes the findings – carries out its own analysis.

Meanwhile, the most important unelected officials in the EU, often criticised for their grand lifestyles and generous allowances, are getting a taste of what it is like to queue up in the cafeteria for coffee – or even to drink tea.

The tests commissioned in Austria by Alexander Just, an archivist with a background in biology, suggested that in every cup that he tested he found up to 175 times the recommended intake of nickel and doses of lead that were 16 per cent above the level considered safe.

“The result was shocking,” Mr Just wrote to the Office of Infrastructure and Logistics at the European Commission. “Two parameters of heavy metals are above the legally allowed limit for drinking water and therefore should not be used for drinking any more.”

Members of staff in the Berlaymont headquarters of the European Commission in Brussels have been sent a helpful medical note advising them of the symptoms of high nickel doses. It states: “Nickel is eliminated from 7 to 40 days after absorption, depending on the quantity absorbed and length of exposure to the metal. Effects are specific, especially for people with allergic tendencies. The most typical outward signs are skin problems or gastrointestinal disorders.”

A commission spokesman defended the decision to buy the machines, which were installed in January in the private offices of the 27 commissioners including the President, José Manuel Barroso.

The spokesman said: “How many ministers do you know who queue in the main cafeteria and is that a good use of their time? The commissioner is not sitting there all day drinking coffee, it is served to visitors. The machines are obviously more expensive than the sort of machines you or I have, but they are designed for greater use. I would suggest it is a sensible use of public money because we do not want to have commissioners wasting time in queues.”

He added: “The company [Cimbali] is saying that the tests were not carried out in the right conditions so they want to carry out their own tests.” Luca Dussi, the operational marketing and communications director for Gruppo Cimbali, said: “Our products are in compliance with all the international required standards.”

The European Commission’s problems with coffee machines are the latest hitch at its Brussels headquarters. Officials admitted in 2006 that 1,000 sq m (11,000 sq ft) of illegal nonsustainable wood sourced from the Indonesian rain-forest had been used for the 13th floor, where the president’s suite is located.

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