NEW YORK: Some of the biggest brand advertisers in the US are suspending their marketing campaigns on Google and YouTube as the controversy about ads being served on extremist websites spreads from Europe.

First reported by The Times in February, it emerged that ads for some leading brands, such as automakers Jaguar Land Rover and Mercedes, were served on a pro-Islamic State video posted on YouTube.

Since then, the scandal has grown to the extent that 250 brands and organisations in the UK have ceased advertising on YouTube, including the British government, Toyota, McDonald's and Tesco, the UK's largest retailer.

The issue has been a hot topic of discussion at this week's Advertising Week Europe event and led to Matt Brittin, President of Google EMEA, having to make an apology.

Then on Tuesday, Philipp Schindler, Google's Chief Business Officer in the US, also apologised to advertisers about the placement of ads next to extremist content.

"Recently, we had a number of cases where brands' ads appeared on content that was not aligned with their values. For this, we deeply apologize. We know that this is unacceptable to the advertisers and agencies who put their trust in us," he wrote in a blog post.

Although Schindler went on to promise an extensive review of Google's advertising policies and tools, and to hire significant numbers of staff to review questionable content, it appears these measures have not been enough to placate some very important US advertisers.

As reported by The Times, these now include Johnson & Johnson, the pharmaceutical and consumer goods giant, mobile phone operator Verizon, AT&T, the world's largest telecoms company, car rental firm Enterprise, and GSK, the UK pharmaceutical group that has an extensive presence in the US.

Verizon, which spent $2.5bn on advertising in the US in 2015, has suspended its entire digital advertising operation after discovering that its brand appeared on controversial YouTube videos.

The Times said these included videos posted by Wagdi Ghoneim, an Egyptian cleric suspected in the US of illegal fundraising, and Hanif Qureshi, whose teachings are reported to have inspired the assassination of a Pakistani politician.

Commenting on the action taken by leading US brands, Pivotal Research analyst Brian Wieser said: "This has ramifications across the digital advertising market. Google don't seem to fully comprehend the scale of concern. The scrutiny is now going to be substantially greater."

According to The Times, other major US brands which have been advertised on extremist websites include KFC, the quick service restaurant chain, and Beam Suntory, the maker of Jim Beam whiskey.

Consequently, Beam Suntory is suspending all of its advertising on YouTube while KFC said it is urgently reviewing its position.

Data sourced from The Times, Google; additional content by Warc staff