Another member of the committee that regulates MPs' conduct was facing questions over his expenses.
Andrew Dismore reportedly claimed £34,000 in second home expenses for a west London flat, which hosts his girlfriend's homeopathy surgery, while declaring a property just a few miles away in his north London constituency as his main home.
Mr Dismore - who serves on the Commons Standards and Privileges Committee - then allegedly "flipped" his second home designation to the north London property and claimed a further £31,000.
The Labour MP for Hendon split a total of £65,000 in second home allowances between the two London properties over an eight-year period, according to the Daily Telegraph.
Mr Dismore released a statement saying: "It was my intention when I bought the Hendon flat for it to be my main home.
"After about 18 months it became clear to me that with increasing parliamentary demands on my time I was spending more time in London than in Hendon, so it was the right thing to do to designate the Hendon property as the second home and the London property as the main home.
"The London home was not a homeopathic surgery. This arrangement continued till I ceased claiming for Additional Costs Allowance (ACA) at the end of the financial year 08/09.
"The Hendon property was cheaper to run, which was also an important consideration to me, and my claims progressively and rapidly reduced year on year since then.
"Although I could have claimed more I did not do so. Although not yet published, for my last year of claim 08/09 the total amount was just under £3,000.
"This is less than London weighting allowance for that year, which I could have claimed as an alternative. Neither property has been sold at any stage."
Sir Alistair Graham, the former chairman of the Committee on Standards in Public Life, told the newspaper that members of the conduct watchdog had to be "squeaky clean".
Last week Tory backbencher David Curry stepped down as its chairman and referred himself to the Parliamentary Commissioner for Standards amid allegations he had claimed £30,000 for a constituency property which his wife had banned him from using after an affair.
"Its longest-standing member having question marks over his own claims does not fit with this. I think the only sensible thing for (Mr Dismore) to do is follow Mr Curry and stand down," Sir Alistair said.