Baroness Goudie, a Labour peer and party fundraiser, has lived since childhood in London, where her two sons grew up and her husband works as a leading barrister.
But when submitting House of Lords allowances, she claimed her main address was a Glasgow apartment.
This has allowed Goudie to claim subsistence allowances intended as payments for those outside the capital, who need help to meet the cost of accommodation in London. Goudie acknowledged she did not spend much of her time in her 200,000 Glasgow flat, although she was there "frequently".
Since public records of peers' expenses were first published in April 2001, Goudie,63, has recorded that her main home is in Glasgow.
Including an estimated amount for 2008-9 expenses, the Glasgow address has enabled her to recoup over 150,000 in accommodation expenses from the Lords over the past eight years. She also claimed an estimated 80,000 for travel between London and Glasgow.
Goudie has strong associations with Scotland. She is a former member of the Court of Napier University and used to serve on the board of a Glasgow hospice. She appeared on a newspaper list of "powerful women" in Scotland five years ago because of close links to senior Labour politicians and was secretary of the Scottish Industry Forum, which raised money for the party. Goudie herself has given 16,000 to Labour.
On Friday, Goudie issued a statement saying she had stayed at the flat recently with her husband and would be there again "shortly".
She wrote: "If anyone says that much of the time I am not at my Glasgow apartment that is true. The same could be said of our London property. I do not count nights or days."