A transaction that saw €15m transferred within Anglo Irish Bank to act as security against a loan to Sean FitzPatrick's family should be investigated, according to a High Court official.

The money had been used to back up a loan for a Nigerian oil investment. It is understood the transaction was agreed with Anglo Irish Bank.

A court-appointed official, who is overseeing Mr FitzPatrick's bankruptcy, has questioned the transaction in a document circulated to creditors today.

The former Anglo Irish Bank chairman made an investment in a Nigerian oil field with Lar Bradshaw, who was also a director of the bank.

Their €27m loan was backed with cash of €21m, which was held on deposit by Anglo.

The bank was nationalised in January last year.

In February, Anglo agreed with Mr FitzPatrick that his €15m cash could be moved to act as a security against loans to his family.

An official was appointed by the High Court to oversee Mr FitzPatrick's assets when he was made bankrupt.

In the report, the official has said it is necessary to investigate the transaction and consider whether it amounted to a settlement under the Bankruptcy Act.

He said the transaction was on 'very beneficial terms' to Mr FitzPatrick's wife and three children.

The effect of the transaction was to make Mr Bradshaw liable for the entire €27m loan.

In its annual report, Anglo wrote off €21m, which it said it was owned by Mr Bradshaw.

The bank said this evening that it is unable to comment due to client confidentiality.