America's Audit Bureau of Circulations could be in for some tough questioning from the industry in the days ahead.

It faces criticism following revelations that two Chicago newspaper groups, the Sun-Times and Tribune, misreported their circulations.

Hollinger International's Chicago Sun-Times faces legal action from advertisers after recently admitting its sales figures were inflated.

The paper, part of the group once headed by discredited media magnate Lord Conrad Black, subsequently announced its circulation manager had resigned.

Amidst indications that the problem dated from at least 2001 it also revealed a former circulation supremo, currently publisher of a smaller local newspaper, was on "administrative leave".

The Tribune Company launched its own inquiry after discovering problems at New York title Newsday and Spanish-language daily, Hoy.

Data sourced from: New York Times; additional content by WARC staff