Media agencies are calling for fast action from the Audit Bureau of Circulations following tit-for-tat accusations from Associated Newspapers and News International over the dumping of free newspapers on London streets.
The call for an investigation came after Associated accused its rival News International of a "systematic and widespread" dumping of copies of its title thelondonpaper. In return, News International issued a series of pictures of dumped copies of Associated's London Lite and made a statement accusing Associated of "crude propaganda".
Chris Amor, the head of press at OMD UK, said: "If there is an element of rogue dumping, then the ABC needs to get to grips with it quickly and take action."
After hiring an ex-Scotland Yard detective to investigate, Associated claimed to have found evidence of three incidents of thelondonpaper vendors dumping a total of 2,900 newspapers. Earlier this week, it posted video evidence on YouTube.
Steve Auckland, the managing director of Metro and London Lite, said News International is "desperate and oversupplying the market". Associated also claimed that advertisers will be "horrified".
However, Amor said advertisers were realistic: "You know with the free distribution model that there will always be a rogue element, although we are concerned there is too much pressure on the distributors."
Ian Clark, thelondonpaper's general manager, accused Associated of over-reacting and waging a campaign to "destroy competition in the London marketplace". He added: "This is an issue with free distribution all over the world. It's not a major problem, and Associated knows that."
Clark said thelondonpaper had more than 40 supervisors to oversee its 450 distributors, and that any vendor guilty of dumping copies would be sacked.
He added: "It took a Scotland Yard detective and a team of five to find 3,000 dumped copies. But it's also a problem that's in Associated's backyard and it knows it."