Solicitor Michael Lynn, whose practice has been shut down by the Law Society, took out at least three mortgages against the same property in the space of a month.
The High Court has been told that each of the mortgages was for almost the full value of the house, which was valued at around €5.5m.
The mortgages were given on a property known as Glenlion House, which is located on Thormanby Road, Baily, Howth, Co Dublin.
Mr Lynn got three mortgages against this property in April 2007.
He drew down a mortgage from Irish Nationwide on 4 April and a mortgage from Bank of Scotland Ireland on 20 April. Mr Lynn then took out a mortgage with another financial institution for the same property on 24 April. The court was told there may be a fourth loan against the same house although that has not yet been confirmed.
The High Court heard that around ten financial institutions lent money in respect of 78 properties in Ireland and one in the UK.
The banks received 155 undertakings in relation to these properties.
The court heard that Mr Lynn has not complied with an order from the High Court directing him to indicate his knowledge of these undertakings and to furnish a copy of all the undertakings. It was told that Mr Lynn had not complied with this order because he is invoking his right not to incriminate himself.
Mr Justice Richard Johnson directed that he should comply with the order within ten days.
The financial institutions are now involved in what was described as a 'competition' to register the properties offered to them as security for loans they issued.
Lawyers for Bank of Scotland Ireland asked Mr Justice Johnson to change his order to allow Mr Lynn to comply with the undertakings he gave to them. IIB Homeloans asked the high court for permission to bring the same issue before the Commercial Court.
The two banks want Mr Lynn to sign the necessary documents to allow them to register mortgages on the properties he offered them as security.
However, many of the other financial institutions objected to this.
Lawyers for Irish Nationwide said this could allow banks to 'jump the queue' in terms of trying to get their money back.
Many of the properties, the court was told, would be subject to competing claims from several financial institutions.
