Alliance Party member Patrick Brown was due to deliver testimony before the Assembly standards committee prior to his surprise resignation as an MLA.
The South Down representative resigned with immediate effect on Tuesday citing “personal reasons”.
The Standards and Privileges committee was due to hear testimony on Wednesday and consider a complaint against a member. Sources said a complaint was made against Mr Brown.
The complaint centred on questions asked by Mr Brown in his position as an MLA in relation of the governance of schools. The complaint was linked to a school in his constituency.
Mr Brown, in a statement announcing his resignation, said: “I am proud of my track record as a constituency MLA and remain committed to Alliance values, and look forward to seeing the party continue to grow across Northern Ireland.
“This May, I will have been an elected representative for 10 years and feel the time is right to step aside for personal reasons.”
The former MLA did not want to make any further comment at this stage.
The Alliance Party was contacted for comment on Mr Brown’s appearance before the standards committee. Following the announced resignation, the party thanked Mr Brown for his service and wished him “well in his future endeavours”.
Earlier this year, Mr Brown was censured by the local government commissioner for standards over comments he made on the interview process that led to the appointment of the Newry, Mourne and Down District Council chief executive.
It came after he posted on social media how he believed councillors had voted on the senior appointment to Newry, Mourne and Down District Council. Mr Brown issued a written apology following an investigation.
Mr Brown was elected to the assembly in 2022, the party’s first ever MLA in the South Down constituency.
The party has seven days to co-opt a replacement, with several names in the mix, including three councillors.
Newry, Mourne and Down Councilor Cadogan Enright is regarded as popular and a successful vote getter. He first represented the Greens and then as an Independent before joining the Alliance.
Castlewellan man Andy McMurray and Tierna Howie, formerly Kelly, are two other names mentioned locally as the mostly likely to replace Mr Brown.