The Liberal Opposition plans to ask police to investigate the outstanding riding office expenses of Campbellton-Restigouche Centre MLA Greg Davis.
Davis received a loan of more than $5,000 from the Progressive Conservatives to cover his office rent in 2012.
But he still hasn't repaid the amount in full, despite also being reimbursed for the expense by the Legislature.
Liberal Deputy House Leader Victor Boudreau says the taxpayers' money remains unaccounted for, following a review by the legislative administration committee.
He challenged the Alward government on the issue in the Legislature on Friday and told reporters afterward he will ask the RCMP to investigate.
"We were giving the premier one last chance to answer the questions. He refused to answer them. We gave him one chance to accept to refer this to the RCMP. He declined that as well, so we will be doing that," Boudreau told CBC News.
"I doubt it will be today. It will probably be early next week by the time we're able to put something together, but we certainly will be referring this to the RCMP for an investigation," he said.
Davis has not been seen at the Legislature this year and has announced he is not running in the September provincial election, citing illness.
The government introduced new legislation earlier this week that will force MLAs to adhere to new rules on reporting their expenses and other costs from their constituency offices.
Davis’s questionable expenses came to light in March when office furniture in his Campbellton-Restigouche Centre constituency office was briefly seized by sheriff’s officers for non-payment of $6,665, representing six and a half months of rent from September 2013 to March 2014.
CBC learned that the Progressive Conservative party helped Davis pay an outstanding five-month rent bill at his constituency office in 2012.
Davis expensed $4,000 for four of those months and was reimbursed, but he still hasn't repaid the party in full.
A report into the office expenses of Davis showed taxpayers did not pay anything extra for Davis’s rent problems this year — but also said the rookie MLA claimed some rent expenses in 2012, even after the PC Party of New Brunswick had already covered them.