This article is more than 11 years old

This article is more than 11 years old

Eleven days of revelations about MPs' expenses published in the Daily Telegraph and Sunday Telegraph have boosted circulation at the papers by more than 600,000 copies, unofficial industry figures reveal.

The continuing upswing in circulation has shown little sign of diminishing and comes as the Metropolitan police said yesterday that it will not investigate the leak of information to the Telegraph titles.

Senior officers ruled that a criminal investigation into how a terabyte of data containing 2m documents was removed from the House of Commons and given or sold to the Telegraph Media Group would not be in the public interest.

Commons authorities called in the Met to investigate, but Scotland Yard yesterday said that although the unauthorised disclosure of information appeared to "breach public duty", much of the information was in the process of being prepared for release under the Freedom of Information Act.

Telegraph Media Group has neither confirmed nor denied whether it paid for the information on MPs' expenses. Estimates on a price tag have stretched from £70,000 to £300,000, although the payment is believed to be at the lower end of this range.

Monday's Daily Telegraph, which covered the secret mortgage payouts of MPs and details about the speaker Michael Martin's staff, sold about 57,000 copies above its regular base, according to initial industry figures.

The Sunday Telegraph sold an extra 56,000 copies at the weekend when it detailed the expenses claims of MPs that attempted to block the freedom on information requests for the expenses data.

On Saturday the Daily Telegraph, which featured the expenses claim for MP David Chaytor, who claimed £13,000 for a mortgage that he had already paid off, was up about 42,000 copies. The day before, Friday 15 May, the Daily Telegraph published the expenses claims of justice minister Shahid Malik, who has stepped down after receiving discounted rent, boosting sales by 74,000 copies.

Friday's sales boost was the second-best circulation increase since the first day of the investigation a week earlier, 8 May, when sales soared by about 87,000 copies.

On Thursday 14 May, details of Labour MP Elliot Morley, who claimed £16,000 for a mortgage that did not exist, sent sales up by about 65,000 copies; while on Wednesday 13 May, the Daily Telegraph covered the expenses of several Liberal Democrat MPs, sending sales up by 37,000 copies.

Tuesday 12 May's revelations about Tory grandees' claims, which included £2,000 by Douglas Hogg for his moat to be cleaned and £380 spent on horse manure by David Heathcoat-Amory, boosted sales by about 51,000 copies.

The stories on Monday 11 May about the Conservative leader, David Cameron, and the shadow cabinet are understood to have added a "significant" number of additional sales, with early estimates suggesting additional circulation of 49,000 copies compared with a regular Monday circulation.

The 10 May edition of the Sunday Telegraph, with its revelations about Sinn Fein, had a circulation 34,000 copies higher than the previous week.

Circulation of the Daily Telegraph on Saturday 9 May, the second day of revelations that focused on Labour ministers, rose by 52,000 copies on the previous week, according to unofficial figures seen by MediaGuardian.co.uk.

All figures are initial estimates and subject to change and have not been certified by the official industry body, the Audit Bureau of Circulations. Official circulation figures for May will be published by ABC early next month.

In April the Daily Telegraph sold an average of 817,692 copies each day, according to official ABC figures for last month, with the Sunday Telegraph averaging a circulation of 590,970.

• To contact the MediaGuardian news desk email editor@mediatheguardian.com or phone 020 3353 3857. For all other inquiries please call the main Guardian switchboard on 020 3353 2000.

• If you are writing a comment for publication, please mark clearly "for publication".