Six people remain under criminal investigation over Northern Ireland's biggest ever property sale, according to the head of the National Crime Agency.
NCA Director General Lynne Owens told the Policing Board in Belfast on Thursday that investigating allegations of corruption and financial irregularities around the £1.2bn deal is a top priority.
While seven people have been interviewed under criminal caution by NCA officers examining the purchase of the Nama northern loan book, six are said to still be deemed suspects.
Ms Owens added that two people were arrested and interviewed under caution in May, but were subsequently released.
However, she said: “No inference should be drawn on the decision to release these people on bail.”
Some 40 witnesses have also been interviewed, while eight properties have also been searched and a number of court orders have been obtained to gather material from members of the public and private institutions.
Ms Owens said: “At this stage, we cannot rule out further arrests, further searches, further interviews or further court orders.”
She also said they had not and would not be naming any of those arrested or interviewed.
The NCA took over the Nama inquiry from the PSNI last July and is working with other law enforcement agencies across Ireland, the Isle of Man and USA.
Nama was established in Ireland at the height of the financial crisis to take property-linked loans off the books of bailed-out banks.
It sold 800 property loans to Cerberus, a multi billion-pound fund, and all parties involved in the 2014 transaction have denied wrongdoing.
WATCH: UTV Correspondent Jane Loughrey reports