A Pricewaterhouse Coopers report into the scheme says both firms were told by a quarry that no English Portland stone, which should have been used, had been ordered. Had they responded, the subsequent use of paler French stone could have been avoided.
After being contacted by Albion Stone Quarry, each firm said stone procurement was not its responsibility and asked the quarry not to contact it again.
Although the report exonerates both firms, and the museum, of a cover-up, it states: "We believe it is unfortunate that these early indications of problems were not followed up by the professional advisers. The procedures put in place by Mace and Foster and Partners did not detect the use of a non-Portland stone and Easton Masonry [the stonemason] continued with the contract." Communication difficulties between the team and its client, the British Museum, are also highlighted. The report says that in March 1999, Mace responded to a tip-off that the wrong stone had been ordered by requesting a series of tests, but Foster and Partners was not formally notified until May.
It is unfortunate that these early indications of problems were not followed up
By the time it was discovered that the French stone was being used, work had begun.
Foster and Partners' role in the £100m scheme is also questioned. The report says that, although the architect should have reported to the project manager, "they appear to have been treated as if they were members of the museum's Great Court Client Committee and, separately, reported direct to the Trustees".
Mace and Foster were unavailable for comment.