The government company that ultimately controls Nama has converted its direct equity stake into a loan, the Department of Finance has confirmed.

Nama was set up last year with the state pledging €49m for a 49% minority stake in the so-called master special purpose vehicle that owns the asset management agency.

Private investors invested in their 51% majority stake, which meant Nama's purchase of commercial property loans would not count toward government debt.

But the Department of Finance unexpectedly reclassified its equity stake into a loan in recent weeks.

Lorcan Roche Kelly, a leading expert on government finances who unearthed the reclassification in last week's issue of the exchequer returns, said he suspected the new treatment was aimed at ensuring Ireland maintained a minority stake in the special purpose vehicle.

A spokeswoman for the Department of Finance said that the new treatment would not affect the ownership of the Nama master special purpose vehicle.

"It was felt that it would be more appropriate that the monies advanced be classified as a loan to Nama as opposed to share capital acquired as this share capital isn't directly held by the exchequer but held by Nama," she said.