An Irish investor who claimed last year to have bought a major building in London for £1 billion (€1.24 billion) residential development in Canary Wharf has insisted confidential material surrounding the deal has been leaked.

Tom Ryan was reported last year to have offered £100 million for the Hertsmere building, which has planning dating back to 2008 to be demolished and replaced by a 74-floor apartment block – which would be Europe's tallest, if built.

However, the deal collapsed and the building has now been bought by Greenland Group, a Chinese state-owned corporation that has invested £1.2 billion in London's booming commercial and residential property market.

Now, it has been alleged that Credit Suisse will face legal action from some of the people who were approached to fund the development – a charge which Mr Ryan's spokesman has said is "fundamentally and factually incorrect".

Various domiciles

Little is known about Mr Ryan’s background, while his spokesman was unable to say yesterday where he lives: “He is a very wealthy man who lives between various domiciles,” he said.

Meanwhile, Credit Suisse said an internal investigation into allegations that were made about the bank’s involvement by some of those who were approached for funding, including London-based property investors the Candy brothers, are still ongoing.

“We acted swiftly when an allegation of wrongdoing was brought to our attention. We are unable to comment further due to ongoing investigations. The individual involved is no longer with Credit Suisse.”

The sale of the “exceptional” property to Greenland – which is building in 80 countries currently – highlights “the ongoing overseas investor appetite” for landmark London deals, said auctioneer Jones Lang LaSalle.