Around 30 protestors gathered at the Fire Service College at Moreton-in-Marsh, Gloucestershire, around 25 miles from the university site, following an anonymous tip-off.
A Speak spokesman said: 'Workers are transported in by a carefully guarded convoy of mini buses each day, leaving the College at 6 am every morning.
'We are confident that it is only a matter of time before we are able to identify the individual companies involved in the build.'
The group plans to protest outside the accommodation again on Saturday and said it was 'confident' that the Fire College would withdraw its support for the project.
The spokesman added: 'We are also confident that the precise location of the depot where the materials to be used in building the new lab are being stored will soon be identified.'
Last Friday the High Court granted a stricter injunction against activists protesting over the new centre.
The original contractor, Montpellier subsidiary Walter Lilley, pulled out of the project in July 2004 due to threats to shareholders.