The DUP's William Humphrey said it was "time for open, honest and forthright confessions" regarding the disappearance of victims of the Troubles, on 16 October 2012.
Mr Humphrey was proposing his party's motion calling on anyone with information about the location of the bodies of the Disappeared to co-operate fully with the Commission for the Location of Victims Remains.
He said that although 12 bodies had been recovered, seven remained to be found.
Mr Humphrey said those with information should "bring some long overdue closure and comfort" to the families of the deceased.
He said he had a fair idea that there were members of the house who knew more about the Disappeared, or knew those who knew.
Mitchel McLaughlin of Sinn Fein said he supported the motion.
He quoted from an IRA statement accepting responsibility for the deaths, and said he wanted to commend and support all the families concerned.
"We should work together rather than try to score points off each other," he said.
Ulster Unionist Ross Hussey said the IRA had a policy of retaining the bodies of its victims.
"Nothing, absolutely nothing justified the retention of these bodies," he commented.
Colum Eastwood of the SDLP said he wanted to follow the lead of the families.
"They are not seeking revenge. They are seeking information," he said.
Chris Lyttle of Alliance said the families "have been denied the most basic human dignity of being able to bury their loved ones".
He said there was no impediment to people supplying information to the commission.
The TUV's Jim Allister accused Mitchel McLaughlin and Sinn Fein of "weasel words"
The motion was carried on an oral vote.