The National Assets Management Agency has lodged a new complaint about its former adviser Frank Cushnahan to the Standards in Public Office Commission.

The complaint follows revelations in a BBC Spotlight investigation which used a series of taped conversations.

On Friday, NAMA made a formal complaint to gardaí on the same matter.

A Comptroller and Auditor General report into the sale of NAMA's Northern Irish loan book will be published tomorrow.

The 2014 sale of NAMA's Northern loans, known as Project Eagle, to US investment company Cerberus Capital Management has been mired in controversy.

The C&AG report into the deal is said to have found shortcomings and irregularities which could have resulted in hundreds of millions of euro being lost.

It is understood NAMA will dispute these findings.

This is the second complaint by NAMA to SIPO about Mr Cushnahan.

The first related to Section 17 of the Ethics in Public Office Act and whether Mr Cushnahan made all required disclosures whilst a member of the NI Advisory Committee of NAMA.

Seán Fleming, the chair of the Public Accounts Committee, has meanwhile proposed a collaboration with the committee and the Stormont inquiry into the matter.