The PSNI has said it is considering whether a criminal investigation is required in relation to Stormont Covid-19 grants which were issued in error.
It emerged this week that three Sinn Féin offices received £10,000 payments from the Small Business Grant Scheme.
On Thursday, former Foyle MP Elisha McCallion resigned as an Irish senator, while two other party officials also left their posts.
MLAs and MPs are not eligible for the grants.
DUP MLA Gary Middleton told BBC NI's The Nolan Show he had contacted PSNI Chief Constable Simon Byrne on Friday morning to ask for an investigation.
The PSNI confirmed "a communication was made to the chief constable in relation to Covid-19 grant money" and it was "considering the matter".
Sinn Féin President Mary-Lou McDonald has apologised for her party's "failures" in its handling of money received under the Small Businesses Grant Support Scheme.
Payments from the fund were sent out automatically to 7,000 bank accounts, but it has emerged that some of the accounts which received the money were ineligible.
Elisha McCallion said she returned the money on Tuesday and apologised "unreservedly".
"I fully accept that as a named signature on the account that I should have taken extra steps to verify this situation, before it was brought to my attention on Tuesday," she added.
Meanwhile questions are still being asked about a payment made to the office of Sinn Féin MLA for West Tyrone Maolíosa McHugh.
The party said a West Tyrone official "who had responsibility for the administration of the account and failed to promptly return the grant money despite being requested to do so" by the MLA had resigned.
On Friday the Department of Finance confirmed a payment "was made in error to ratepayer name - Maolíosa McHugh MLA - Strabane Sinn Fein Office", which was repaid in full earlier this week.
However it is understood that Mr McHugh's name was not on the account into which the payment was named.
The DUP, SDLP, Ulster Unionist Party and Alliance have all said that none of their MPs or MLAs received money from the scheme.
On Thursday, First Minister Arlene Foster said the landlord of a DUP office may have received a grant and urged them to repay it "because it is public money".
"It was put in place to help businesses that were struggling at that time, so there is no way politicians or landlords should have been in receipt of that money," she said.
"They have a moral and legal duty to pay that money back."