class="story-body__introduction">Google's European boss has apologised after adverts from major firms and government agencies appeared next to extremist content on its YouTube site, according to BBC.It came after Marks and Spencer became the latest firm to pull its online ads over the issue, joining others such as Audi, RBS and L'Oreal. Google's European chief, Matthew Brittin, promised to review the firm's policies and strengthen enforcement. But some questioned the company's commitment to tackling the issue. A recent investigation by the Times found adverts from a range of well-known firms and organisations had appeared alongside content from supporters of extremist groups on YouTube's video site. An advert appearing alongside a video earns the poster about £6 for every 1,000 clicks it generates, meaning brands may have unwittingly contributed money to extremists. The Times said that rape apologists, anti-Semites and hate preachers were among those receiving payouts.