Unidentified informants have told the Irish Bank Resolution Corporation they have information that the family of Sean Quinn has hidden assets with a value of up to €500 million, the High Court was told today.

Under court orders last year the family disclosed assets with a total value of aprpoximately €1 million, an amount the bank says is inherently implausible.

The bank, which is now in liquidation, did a deal with the two informants last year whereby they are to get 3 per cent of any cash recovered as a result of their information.

Mr Justice Peter Kelly was told today “gagging orders” that applied to orders sought earlier this year in London and Delaware, in the US, have now been lifted and the bank was now informing the court. It would be informing the Quinn family about the development later today, the court heard.

The UK and US orders resulted in the IBRC liquidators getting information about email traffic between particular email addresses which, the court was told, include a large number of emails between parties connected with a “scheme” which the bank believes is part of a conspiracy on the part of the Quinn family to put substantial assets beyond the bank’s reach.

One of the two special liquidators to the IBRC, Kieran Wallace, told the court by way of affidavit that the identities of the informants "and their source" had not been disclosed to the English or US courts as he believed, and continues to believe, that they would be at substantial personal risk if their identities were revealed.

Paul Gallagher SC, for IBRC, told Mr Justice Kelly that Mr Wallace had concerns about the informants' safety given the "numerous reported attacks on the former Quinn Group and employees of the Quinn Group."

These concerns meant he did not want to reveal the informants’ names to the court. Mr Wallace said that in his affidavit to the English court, he did not allege that the risk to the informants emanated from the defendants in the case, who are in the main members of the Quinn family.

The informants said they had information concerning bank accounts and an investment in gold. Transactions involving a certain individual in Investec Bank formed part of the London application. However the material uncovered had not disclosed any such transactions.

Mr Wallace told the courts in England that one of the informants was once charged with a criminal offence, but acquitted.

Sean Quinn, his son Sean junior, and his nephew Peter Darragh Quinn, were found in June 2012 to have been in contempt of court in relation to the movement of assets beyond the reach of the IBRC and were sentenced to periods in custody.

While Mr Quinn and his son went to jail, Peter Darragh Quinn "fled the State on the morning of his commital hearing and remains at large," Mr Gallagher said.

The family has told the courts that while it did at one stage seek to put assets beyond the bank’s reach, it had since then lost control of many of the assets.

The bank told the court today extensive email material recovered by the bank shows traffic between a number of parties, including an address, nigel.smith@london.com, which the informants said was “an alias email address used by the Quinn family.”

The email traffic spans the period June 2012 to February 2014 and includes emails to an address used by Peter Darragh Quinn, an address called quinn.assets@irelandmail.com, and a large number of emails to addresses linked to Michael Waechter, a Dubai-based businessman who has repeatedly denied any involvement with the alleged conspiracy scheme.

Mr Gallagher told Mr Justice Kelly the bank had the details of the email traffic, and expected to get the actual content of much of the emails next week by way of the US court.

Mr Justice Kelly thanked Mr Gallagher for the update on developments, which he said he would note.