OTTAWA - An anonymous opponent is targeting Liberal Leader Michael Ignatieff with a rather pricey political prank laundered through a BBC mailing address.

Members of the parliamentary press gallery recently received a mass mailing of plain brown manila envelopes, postmarked London.

Inside, without cover letter or explanation, was a colour reproduction of a critical, four-year-old Ignatieff profile in the British publication New Humanist -- complete with particularly damning paragraphs highlighted in yellow.

The only clue to the mailing's origin was the London postmark and a return address sticker, which an Internet search quickly pinpointed as the location of BBC TV's head office.

The British Broadcasting Corp., dismissed the address as a subterfuge, noting all BBC correspondence uses franked envelopes -- not the postage stamps found on the anonymous mailout.

"The BBC is a non-political organization so does not take a view on Canadian politics, so we would not comment further on this issue," the BBC said by email.

Ignatieff's office assumed the Conservative party was behind the mailing, albeit without any evidence.

"Between job losses, record bankruptcies and a spiralling deficit you would think the Conservatives would have more important things to do," spokeswoman Jill Fairbrother said in an email.

Dmitri Soudas, Prime Minister Stephen Harper's press secretary, responded to a query to the party with a pointed warning for Ignatieff and his staff.

"I'd suggest that the Liberal party be cautious about making unsubstantiated claims," Soudas said in an email.

"The Conservative party or government did not send these letters about Mr. Ignatieff."

Whoever sent the envelopes had relatively deep pockets for a political prankster -- especially considering the same Ignatieff profile can be found online for free. At about $3.30 Cdn per mailing, postage alone to reach the full Ottawa press gallery would cost more than $1,000.