Detectives were last night searching for two former 'Biospherians' over alleged sabotage at the giant sealed greenhouse, in which researchers are trying to create an entirely separate ecosystem.
It came after an unexpected coup by Ed Bass, the Texas billionaire who bankrolls the dollars 150m ( pounds 100m) project. On Friday Mr Bass, a reclusive philanthropist, arranged for US marshals to raid the Biosphere's offices, 40 miles north of Tucson, to remove the management team of six, including John Allen, his former New Age guru.
Officials at Biosphere named the two people being sought as Abigail Alling and Mark Van Thillo, members of the crew of eight who spent two years sealed inside the complex and emerged last September.
The pair had telephoned to take responsibility for the attack, project officials said. They entered the Biosphere and broke seals, causing its atmosphere to be contaminated with outside air.
The break-in is yet another disaster for the 'planet-in-a-bottle' experiment which has been under fire ever since a crew including two Britons were locked inside the array of domes and pavilions for two years of self-sufficiency, looking after chickens and tending crops. The project has been accused of unscientific methods, internal feuding, and being controlled by a cult which believes that human beings should start afresh on Mars.
Mr Bass appears to have become fed up with his managers' failure to make any profit, despite attracting hundreds of thousands of visitors, each paying a dollars 12.95 fee to gaze through the glass.