A Stormont watchdog is to take legal advice on compelling Nama to appear before it.
The Finance Committee is investigating a £1.1 billion deal to sell the organisation's property loans in the north.
Nama is the "bad bank" set up by the Irish government to clear property loans from bailed-out lenders.
It and all private firms involved in the Northern Ireland assets sale have denied wrongdoing.
Committee chairman Daithi McKay said: "At today's meeting of the Finance Committee inquiry into the sale of Nama's northern portfolio we agreed in principle to use the committee's power to compel witnesses to come to the inquiry.
"It was agreed to compel both Nama and the permanent secretary of the Department of Finance and Personnel to attend the inquiry."
The committee also agreed to invite US investment firm Pimco, which considered buying the properties, to come to the inquiry to answer questions on its involvement in the transactions.
Nama sold the portfolio to US firm Cerberus last year.
Allegations were levelled in the Dail recently by Independent TD Mick Wallace.
Using parliamentary privilege, Mr Wallace alleged that £7 million in an Isle of Man account linked to the deal was "reportedly earmarked for a Northern Ireland politician or political party".
A lawyer involved has denied the money was intended for a politician or relative of a politician.
Read the full background to the £7m Nama scandal
[ Florida drops anti-sectarianism laws over Nama bidOpens in new window ]
[ Robinson involvement in Nama's loan book continued after saleOpens in new window ]
[ Freedom of Information anomaly sparks concernsOpens in new window ]
[ Nama letter shows Cushnahan had "designated assistants at Tughans"Opens in new window ]
[ Peter Robinson's son worked for firm given £9m by NamaOpens in new window ]
[ Sinn Féin's Mary Lou McDonald withdraws committee callOpens in new window ]
[ Nama: Top civil servant 'prefers not to answer questions'Opens in new window ]
[ Simon Hamilton raised Nama issue in meeting with Michael NoonanOpens in new window ]
[ London urges Stormont to "keep a close eye on Cerberus"Opens in new window ]
[ Wallace will give bribe info to gardaíOpens in new window ]
[ Robinson's lobbyist son has 'access all areas' at StormontOpens in new window ]
[ Nama: Sinn Féin Stormont MLA meets National Crime AgencyOpens in new window ]
[ Fresh start for £7m lawyer Ian CoulterOpens in new window ]
[ Industry body calls for lobbyist registerOpens in new window ]
[ Taoiseach questioned over £1.3bn Nama saleOpens in new window ]
[ Stormont's Nama inquiry is a non-starterOpens in new window ]
[ Ex-Tughans solicitor Ian Coulter pictured for first timeOpens in new window ]
[ £7m lawyer says no Nama sale money intended for politiciansOpens in new window ]
[ Ian Coulter's Nama statementOpens in new window ]
[ Nama: Law Society asks to be ordered before Stormont probeOpens in new window ]
[ 'Up to four politicians from two parties' linked to Nama scandalOpens in new window ]
[ The Nama scandal – a timelineOpens in new window ]
[ Wallace prepares to unveil more details of Nama dealOpens in new window ]
[ When the north starts to resemble Craggy IslandOpens in new window ]
[ Nama: What we know, and what questions remain unansweredOpens in new window ]
[ Peter Robinson denies he was to benefit from Nama dealOpens in new window ]
[ Frank Cushnahan was 'well known and well placed'Opens in new window ]
[ Nama: Simon Hamilton criticised over Cerberus meetingOpens in new window ]
[ Martin McGuinness 'unaware' of Robinson Nama letterOpens in new window ]
[ £5 million Frank Cushnahan Nama fee 'arrangement' revealedOpens in new window ]
[ Law Society 'silliness' over handling of Tughans probe criticisedOpens in new window ]
[ First Minister's son breaks silence on Nama dealOpens in new window ]
[ National Crime Agency to lead probe into Nama claimsOpens in new window ]
[ McGuinness kept in dark over Robinson's Quayle meetingOpens in new window ]
[ Nama: PSNI probe into 'potential criminal activity'Opens in new window ]
[ Loyalist blogger facing legal action over DUP claimsOpens in new window ]
[ Peter Robinson could face Stormont Nama probeOpens in new window ]
[ No signs of life at Gareth Robinson's publicity-shy PR firmOpens in new window ]
[ Secret Cerberus meetings between Peter Robinson and ex-US Vice PresidentOpens in new window ]
[ Peter Robinson's son worked for Nama deal law firmOpens in new window ]
[ Former Nama member Frank Cushnahan had close ties to the DUPOpens in new window ]
[ Stormont calls for anyone with Nama information to come forwardOpens in new window ]
[ Peter Robinson: I met with US firm over Nama portfolioOpens in new window ]
[ Analysis: Questions in the Nama sale which remain unansweredOpens in new window ]
[ Allister says 'immediate questions need answered on 'NAMAgate'Opens in new window ]
[ TD claims further revelations to come on NI Nama saleOpens in new window ]
[ Peter Robinson: I met with US firm over Nama portfolioOpens in new window ]
[ Secret tapes stored on £7m Nama dealOpens in new window ]
[ Explosive claims about £7m 'earmarked for politician"Opens in new window ]