An Irish government agency has launched a US legal action against former property tycoon Sean Dunne.

The National Assets Management Agency (NAMA) is owed over $250million by Dunne.

Now resident in the US, Dunne was ordered to repay the money by the Irish courts last March.

The legal action centres on claims by NAMA that Dunne transferred properties to his wife Gayle Killilea to keep them out of the agency’s reach.

A hearing is due to be heard in October according to weekend reports in the Irish media.

The NAMA move comes after a luxury US house linked to Mr Dunne’s wife was sold for $5.5m.

The Irish Independent reports that the property is located in one of the wealthiest and most exclusive neighbourhoods in the entire US - Belle Haven in Greenwich, Connecticut.

The area is home to hedge-fund billionaires and Wall Street titans while the paper reports that singer Diana Ross also stays there.

Dunne, who moved to the US two years ago after the collapse of his Irish property empire, has always denied living there.

The report says that the house has been listed in US documents as the home of his wife while neighbours in the wealthy suburb say both Dunnes were involved in a $1million renovation.

The property ‘trustee’ named in the sale documents for the house at 38 Bush Avenue is Thomas J Heagney, Gayle Killilea’s US lawyer.

A $2.5million profit was made on the house when it was sold last July.

The Irish Independent says the Connecticut property was bought for $2million in 2010 with a further $1million spent in extensive reconstruction work that provoked some outrage in the plush neighbourhood.