Searches were carried out in Co Down on Tuesday as part of inquiries into the record £1.2 billion sale of assets and property loans to US investment fund Cerberus by Ireland’s “bad bank”, the National Assets Management Agency (Nama).
The investigation by the National Crime Agency, the UK’s lead policing body, was sparked by the discovery of a £7 million offshore transfer to an Isle of Man bank.
A spokesman said the two men had been bailed pending further inquiries.
A separate investigation into the affair is being run by the US Department of Justice’s Securities and Exchange Commission and p parliamentary inquiries have been carried out in Stormont and Dublin amid a raft of allegations about fixer fees behind the deal.
Irish Taoiseach Enda Kenny rejected calls for a state inquiry, insisting that no allegations of wrongdoing had been made against Nama.
It signed off on the Project Eagle deal in April 2014 by selling 800 property-linked loans to Cerberus, a multibillion fund which boasts former US vice president Dan Quayle in its ranks.
But the sale has been dogged by controversy since allegations were first made under parliamentary privilege that some of the money in the Isle of Man account was destined for a politician.
Further revelations, also under parliamentary privilege, separately claimed £45 million had been earmarked for fixers and there were five beneficiaries of the £7 million.
All parties involved in the £1.2 billion transaction in 2014 have denied wrongdoing.
Cerberus won the auction by offering £1.241 billion for loans linked to the Northern Ireland properties when the reserve price was £1.24 billion.