The National Asset Management Agency (NAMA) has identified more than €42m in assets, hidden by its developer clients.

The discovery was made after private investigators were hired to chase them down.

The Sunday Times reports the state agency identified the haul through asset searches up to the end of last year.

The figures were presented last week to Finance Minister Michael Noonan.

NAMA has spent almost €2m on private investigators over the past four years.

The agency spent €389,000 on asset searches last year - less than half of the €782,000 spent in 2013.

Mr Noonan said the agency used investigators when he believed any of its 800 debtors had not fully declared their assets.