A mysterious donation of £1.8 million to the RIBA and V&A Museum's Architecture for All campaign has left fundraisers amazed.
The cash windfall - said to be from an 'American gentleman' - means the drive to raise £10 million to fund the move of the RIBA Drawings Collection to the V&A has reached the halfway point.
It is understood that the deal, which is shrouded in secrecy, was negotiated through the US-based American Friends of the V&A.
The one-off gift will make up a hefty chunk of the funding required to transfer the drawings and also pay for their new home, designed by Wright & Wright Architects and Gareth Hoskins Architects.
Such is the importance attached to anonymity that not even the chair of the British Architectural Library Trust, Michael Rose, is allowed to know the identity of the donor.
However, he is still extremely pleased. 'Of course we are all delighted to have received such support, ' Rose told the AJ. 'We hope that it will encourage other individuals or groups to come forward with large donations. It would make life a lot easier if six people did the same thing and covered the cost on their own, ' he added.
The cheque - which was finally signed off last week after months of negotiations - will now be added to the £3.27 million from the Heritage Lottery Fund agreed earlier this year.
Details of the deal emerged at the launch of public fund-raising, which includes the Adopt a Drawing initiative. This will allow any individual or company to sponsor parts of the exhibition from the smallest sketch to the entire reading room.
The campaign was launched to find the cash to transfer the priceless Drawings Collection, allowing it to be fully open to the public for the first time.
For further details on Adopt a Drawing, contact Georgina Brown on 0870 060 5504.