Lawyers for IBRC say critical new evidence from partly-destroyed computer hard drives shows the Quinns remain in control of companies in their International Property Group.
They say it is extraordinary for Sean Quinn Jnr to apply to be released from prison by contending he could not comply with court orders aimed at reversing a scheme to strip these Quinn assets.
Today was the second day of Sean Quinn's Supreme Court appeal against his three-month sentence for contempt of a court order put in place to stop assets being moved beyond IBRC's reach
IBRC counsel Paul Gallagher said today that new evidence from partly destroyed computers found in Moscow shows the family remain in control of the companies they say they lost control of.
He said the evidence demonstrated the Quinns handled money and rents even during the contempt hearing before the High Court last summer, and obtained huge payments of money.
It had been submitted that Sean Quinn Jnr was very much involved in managing and directing the actions of IPG companies.
The bank contends a scheme to remove $430m of assets from Quinn companies used "means so serious, and so undermining of the rule of law,", that it had no parallel.