THE health minister is claiming rental expenses from Stormont for a Co Tyrone constituency office owned by her MLA colleague's husband.
Sinn Féin assembly members Michelle O'Neill and Linda Dillon share an office in Coalisland town centre.
In the past four years more than £20,000 has been claimed in expenses for rent of the property.
But The Irish News can reveal the constituency office is jointly owned by three people – one of whom is Mrs Dillon's husband.
New rules on expenses forbid MLAs from claiming rent for offices leased from 'connected persons' such as spouses.
The restriction applies to each assembly member sharing an office.
For years Sinn Féin's rental expenses for the property have been paid to the 'Tyrone Cultural Society'.
It is one of three societies that has received assembly expenses from the party over the years to cover office rental costs.
However, questions were raised in 2014 when a BBC Spotlight programme could not establish what the societies were or who was behind them.
Sinn Féin said the constituency office is in "full compliance" with assembly guidelines and Mrs Dillon's husband received no financial remuneration.
Alan McQuillan, a former member of the Independent Financial Review Panel (IFRP) which oversees the assembly expenses process, questioned the expenses arrangement.
"The key principle here is an issue of transparency. There is a very clear ban on MLAs having any rent paid to a close family member, and the question is who really owns these premises," he said.
"We are still waiting to see what the assembly does in relation to the replacement of the financial review panel.
"The rules are very clear and it is designed to make sure that there is value for money and that rental money is not channelled to parties and individuals associated with the elected members."
Details about the Coalisland constituency office were first filed with Land Registry in May 2011.
Since July 2012 the owners of the property's leasehold have been registered as Brian McLernon, John Clarke and Gerard Dillon.
Mortgage details were also listed against the property.
There were no pending changes due to be made when The Irish News examined the Land Registry details last Monday.
However, a solicitor for Sinn Féin on Friday said the property is owned by the trustees of the Tyrone Cultural Society.
He said: "The property is owned by the trustees of the Tyrone Cultural Society who are at present Mr Brian McLernon and Ciaran McElhone.The premises are let to Michelle O'Neill MLA and Linda Dillon MLA."
A Sinn Féin spokesman said: "Sinn Féin rents its Coalisland constituency offices from the Tyrone Cultural Society in full compliance with assembly guidelines.
"Linda Dillon's husband Gerard was a trustee of the cultural society but received no financial remuneration for that position.
"He stood down from the position in May this year following Linda's election as an MLA."
Mrs O'Neill has been a Mid Ulster MLA since 2007, holding several senior roles the health minister post.
Mrs Dillon, a former chair of Mid Ulster District Council, was elected as an MLA in May this year.
She became one of Sinn Féin's Mid Ulster candidates after Deputy First Minister Martin McGuinness moved to contest the Foyle constituency.
Before her election she had worked since 2007 in the Coalisland constituency office, according to the party's website.
Sinn Féin MLAs have claimed almost £21,000 in rental expenses for the Coalisland office in the last four years in which Mr Dillon jointly owned the property.
Mrs O'Neill claimed £14,850 between 2013/14 and 2015/16. Former MLA Francie Molloy, the MP for the area, claimed £6,098 from 2012/13 to 2013/14.
The rent was paid to the Tyrone Cultural Society.
In February it emerged that the Assembly Commission, a cross-party group that oversees Stormont operations, had cleared Sinn Féin of wrongdoing in paying office rent to three cultural societies.
The commission said its review confirmed the money was for "admissible expenditure".
The findings were at the time described as "bizarre" by TUV leader Jim Allister who had raised the issue.
In previous years there was nothing in the expenses rules that prevented MLAs claiming rent for properties owned by people connected to party workers.
IFRP issued new regulations in March this year.
The latest expense claims from MLAs for the period since May's election are expected to be published next month.
An Assembly spokeswoman said there had been no change in the owners' details.
"The MLAs mentioned are claiming rent under the provisions of paragraphs 11-15 of the Assembly Members (Salaries and Expenses) Determination (Northern Ireland) 2016 and there has been no change in the Constituency Office details."