The facility will run for a minimum of six months, but can be extended to 12 months after which it will be free from early redemption charges.
The funding was granted to a complex offshore structure, while Omni said it expects to be invited to provide indicative terms and pricing for the development funding when the time comes.
The property is close to the Knightsbridge and South Kensington, while the deal was introduced by real estate investment adviser firm Curzon Land.
Colin Sanders, Omni Capital’s chief executive, said: "A particular challenge presented to us was the arcane structure of the special purpose vehicle to which we were lending.
“Also, it proved essential to provide detailed terms quickly to assure the borrower of our funding capacity and understanding of the asset.
"The fact we succeeded on both counts is, I believe, testament to our ability to close complex, high-value transactions of this type with rapidity and efficiency.
"Chris Green [Curzon Land chief executive] played a key part. Our requests for information and documentation were handled skilfully and promptly. The communication process throughout was well-managed and proved pivotal in delivering a satisfactory outcome for all partiesry."