The Financial Times (FT) has issued a warning to advertisers after it discovered the levels of domain spoofing against its site was considerably higher than it could have imagined.

The publisher, which doesn’t sell video ads programmatically, found display ads against inventory pretending to be FT.com on 10 separate ad exchanges and video ads on 15 exchanges. The fraudulent inventory was found to have come from 300 accounts.

The FT found that there was the equivalent of one month’s supply of FT.com video inventory appearing fraudulently in a single day, estimating the value of fraudulent inventory to be £1m a month.

“The scale of the fraud we found is jaw-dropping,” Anthony Hitchings, digital advertising operations director at the FT, told Digiday. “The industry continues to waste marketing budgets on what is essentially organized crime.”

Jon Slade, the FT’s CCO, has notified the exchanges to remove the fraudulent inventory and promised to check back in a month to ensure it had been taken care of. A second letter has also been sent to the FT’s 11,000 client and agency contacts to explain the problem.

The FT’s investigation coincided with its adoption of ads.txt, the Interactive Advertising Bureau (IAB) Tech Lab’s standard to root out fraudulent inventory. Other UK publishers including the Guardian and News UK have also adopted the standard, however uptake has generally been slow.