Police could investigate an MP for fraud over a expenses claim he submitted in 2016.
Chris Davies, who represents Brecon and Radnorshire, said he made "an honest mistake" by claiming for furniture and pictures for his constituency office.
A complaint was made to the Conservative Party in March and was passed to the Independent Parliamentary Standards Authority (IPSA).
Mr Davies said he had repaid £450 after being asked to do so by IPSA.
'Clear my name'
The Metropolitan Police said IPSA - which oversees MPs' expenses - made a referral on 4 April "in relation to an allegation of fraudulent expense claims submitted by an individual".
A spokesman said the matter was "currently subject to an assessment by officers from the Met's Special Enquiry Team".
Mr Davies, who was first elected to Parliament in 2015, attributed the claim to "my inexperience of the IPSA code" and insisted he had never claimed for something he was not entitled to.
He accepted he manually created two invoices in a claim for expenses which he should have entered online, but insists the information had been in the public domain for two years.
"I've apologised for getting the code wrong. I've done nothing wrong whatsoever and I want to clear my name and deal with this," he said.
IPSA said it was "made aware of this issue at the end of March 2018 and we have taken appropriate action, including the recovery of funds".
Mr Davies said he only became aware of the police's involvement when contacted by the Mail on Sunday newspaper on Saturday, but said he would "happily explain the situation to the police".