Some 2,000 or so customers of the ICS Building Society will wake up this morning to find that Bank of Ireland no longer owns their mortgage.

The debts on their homes are now due to Dilosk, which yesterday completed the purchase of a €223 million mortgage book from Bank of Ireland along with the ICS brand and distribution platform.

Not much is known about Dilosk. But it is not a bank. To be precise, it is a Retail Credit Firm regulated by the Central Bank of Ireland.

It was founded by financiers Fergal and Oran McGrath who, along with other directors, are the owners of the company.

The source of the funds they are using to buy the ICS book and fund the other parts of their business is not disclosed but is presumably the debt markets.

The purchase of ICS is just the start of a bigger plan which envisages Dilosk being a player in the mortgage market – or as it puts it on its website: “Dilosk will offer borrowers an alternative source of financing to the traditional banking market.”

That of course is pretty much what ICS was set up to do 150 years ago – provide an alternative source of long-term finance for home purchases by civil servants. Back then, that involved pooling the savings of many under a risk-averse mutual ethos. These days it appears to mean operating outside the regulatory regime imposed on banks in the altogether more risky world of non-bank finance.