Google headquarters in Mountain View, California. Photo: Wikimedia Commons.

A top global advertising agency has withdrawn all of its 240 UK clients from Google websites — including YouTube — due to concerns about ads being displayed next to extremist content, the Times of London reported this weekend.

According the report, Havas — which represents companies such as O2, Dominos and Hyundai, among many others – spends around £175 million a year in the UK on digital advertising, of which Google gets around £35 million.

Google, the report said, failed to give Havas “specific reassurances, policy and guarantees that their video or display content is classified either quickly enough or with the correct filters.”

“We have a duty of care to our clients in the UK marketplace,” Paul Frampton, chief executive of Havas UK, was quoted as saying. “Our position will remain until we are confident in the YouTube platform and Google Display Network’s ability to deliver the standards we and our clients expect.”

Ronan Harris — managing director of Google UK — was quoted as saying his company had “begun a thorough review of our ads policies and brand controls, and we will be making changes in the coming weeks to give brands more control over where their ads appear across YouTube and the Google Display Network.”

Last week, a top Google executive told British lawmakers that an antisemitic YouTube video titled “Jews admit organizing White Genocide” did not constitute hate speech.

While the video — narrated by ex-Ku Klux Klan leader David Duke — was “deeply offensive and shocking,” it did not violate YouTube rules against hate speech and would remain on the site, Google Vice President for Communications and Public Affairs Peter Barron said at a House of Commons Home Affairs Select Committee hearing on Tuesday

The hearing marked the start of a parliamentary inquiry into online hate. Representatives of Facebook and Twitter also spoke before the committee.