A Northern Ireland property developer has made a series of controversial allegations about the behaviour of Cerberus, the US company that bought NAMA's Northern Ireland property book.

Gareth Graham gave evidence to the Stormont committee that is inquiring into the NAMA sale of the Northern Ireland portfolio.

He is a member of the Sean Graham bookmakers family.

He has claimed in his evidence today that Frank Cushnahan, who served on the Northern Ireland advisory board to NAMA, has for several years been a shareholder in a number of Graham property companies.

He also claimed that he has many hours of tape recordings of telephone conversations involving Mr Cushnahan that may be of interest to the authorities.

Mr Cushnahan left his role as chairman of a number of Graham companies in 2008.

Mr Graham said his mother is the main shareholder in the bookmaker business.

She is in the public area of the Stormont Committee room listening to today's proceedings.

Mr Graham said he believes there is a criminal conspiracy against his family. He said a formal complaint is being prepared.