Northern Ireland MPs Iris Robinson and her husband Peter both tried to claim for the same £1,223 expenses bill on the same day.
Mrs Robinson, who once described homosexuality as an "abomination", was exposed in the latest round of expense receipts published by the Daily Telegraph.
The Democratic Unionist Party MPs have come under scrutiny for their financial affairs before, with a tabloid newspaper reporting last month that they claim almost £600,000 a year in salaries and expenses.
The double claim was rejected by officials, as was a claim for a total of £10,860 in mortgage interest payments made by the couple – covering five months – because they did not provide mortgage interest statements as proof. It was not clear whether the money was paid to them or if they eventually submitted evidence of the interest.
Between 2004 and 2008, the couple claimed a total of £159,208 on their east London flat, most of which went on mortgage interest repayments.They bought the flat in 2001 for £450,000.
They also claimed £30,525 for food between 2004 and 2008, reaching the £400 limit most months.
In response, Mr Robinson described the double claim for the £1,223 bill as “an innocent mistake”.
He said: “The two claim forms were prepared for the signature of my wife and myself by the same person. They are signed separately and then sent together in the one envelope. Anyone in the fees office would have been dealing with the claims together and inevitably would have noticed the innocent mistake. It is clear that this one duplicate entry over many years was an innocent error and happily was spotted.”
He added that the £100 per week claims for food were "not unreasonable", although he said none of the couple's children had spent "more than half a dozen nights in the apartment over the years”.
Mrs Robinson earns £63,291 for her position as an MP, £24,296 as an Assembly member and as chairwoman of its health and social services committee and £9,550 as a councillor for the Castlereagh borough in Northern Ireland.
 The Speaker's supporters say he has long been the victim of snobbery. |
A no confidence motion in House of Commons Speaker Michael Martin is to be tabled by a Conservative backbencher.
MP Douglas Carswell is to make the move following a furore over Mr Martin's handling of leaks of MPs' expenses.
Some MPs felt he was more concerned with attacking those who criticised him than responding to public anger.
Labour MP Gordon Prentice argued that the speaker was now "too compromised" by recent events and so should stand down immediately.
 Mr Hogg was one of several Tories whose claims were questioned |
Conservative MP Douglas Hogg has agreed to repay £2,200 - the cost of clearing his moat at his country estate - amid the continuing row over MPs' expenses.
Mr Hogg maintained he had not claimed the money but agreed it had not been "positively excluded" from paperwork submitted to the Commons fees office.
"I believe that my claims fell clearly within the scope of the rules."
He is the latest in a string of Labour, Tory and Lib Dem MPs to pay back money after claims came to light.
Mr Hogg was irritated by the Telegraph's coverage of his own claims - which was included in a series of articles about how wealthy Conservatives had claimed towards the cost of maintaining large constituency homes.
The Telegraph also reports Justice Minister Mr Malik - who claimed the most expenses of all 646 MPs in 2007 - claimed a maximum of £66,827 allowances over three years for his second home in London.
It reports he claimed £2,500 for a cinema system, later reduced by half by the fees office.
He claimed £65 for a court summons for council tax non-payment but he repaid this on Thursday.
Mr Malik said the report's suggestion he paid only £100 a week in rent on his "main home" in his Dewsbury constituency was a "fabrication".
He said the house was where he spent most of his time so it was legitimate to claim for the second home in London.
Andrew MacKay: 'I feel that it is important to apologise'
Conservative MP Andrew MacKay has quit as parliamentary aide to David Cameron over what the party said was an "unacceptable" expenses claim.
He claimed full second home allowance on his London address, while his wife, Tory MP Julie Kirkbride, claimed the full allowance for another home.
Mr Cameron has said all Tory MPs must be able to defend their expenses.
 Elliot Morley was said to be "heartbroken" |
A former minister has admitted he claimed £16,000 on expenses for a mortgage that had been paid off.
Labour MP Elliot Morley told the BBC he had repaid some back and it had been a mistake which he felt terrible about.
The Daily Telegraph reported he claimed £800 a month for a Scunthorpe property for 18 months after the mortgage ended.
More than 20 MPs have said they will pay back claims totalling nearly £130,000, amid public anger after days of revelations from leaked receipts.
Phil Hope: "The public anger has been a massive blow to me"
Health minister Phil Hope is to repay £41,709 in second home allowances following media revelations.
The Labour MP said he had kept to the rules but stories about his expenses had caused a "massive blow" to his integrity and standing with voters.
It is the biggest amount an MP has paid back as all parties attempt to repair the damage to their reputation.
Hazel Blears says public outrage and the need to rebuild trust prompted her decision
Hazel Blears has said she will pay £13,332 in capital gains tax on the sale of her "second home" after criticism about her expenses claims.
The communities secretary told Commons staff her London flat was her "second home" on which she claimed expenses.
But when she sold it she did not pay CGT, due on homes the Inland Revenue does not consider a "main residence".
She said she had acted within the rules but knew people were "really angry" and paying it was "the right thing to do".
Lord Mandelson, who claimed £2,850 for his home, before quitting as an MP and selling it for a large profit, said the claims were for essential repairs. 
Justice Secretary Jack Straw said he had repaid £1,500 which he claimed to cover the full rate of council tax on his constituency home - when he was getting a 50% discount. He told the BBC he had acted "in complete good faith and within the rules" but regretted the "error" on council tax.
Downing Street says there was "nothing wrong" with Gordon Brown's £6,500 claim to pay his brother for a cleaner.
The Telegraph revelations include Communities Secretary Hazel Blears claiming three different properties within a year were her "second home" - the first her Salford constituency, the second two in London. MPs can claim up to £24,000 a year towards the costs of their second home.
