The European boss of Google has apologised for online adverts appearing next to extremist material as big firms, including M&S, pull ads from the internet giant.
Matt Brittin, head of the company for Europe, the Middle East and Africa, said: "We are sorry to anybody that's been affected."
He made the comments at an industry conference after a number of well-known UK brands suspended advertising over concerns centred on content appearing on Google's YouTube platform.
M&S said: "In order to ensure brand safety, we are pausing activity across Google platforms whilst the matter is worked through."
Go Ape - the outdoors adventure firm - said it had suspended its advertising on YouTube after Sky News Business Correspondent Adam Parsons alerted the company to its ads being run alongside English Defence League videos.
Even (Taiwan OTC: 6436.TWO - news) the Government has done the same while global advertising giant Havas (LSE: 0MGT.L - news) , which buys ad space for a number of big companies, suspended advertising last week.
:: What the firms are saying
Other big names to take similar action include McDonald's UK, Tesco (Frankfurt: 852647 - news) and Sainsbury (Amsterdam: SJ6.AS - news) 's, Audi UK, and L'Oreal in the UK and Ireland (Other OTC: IRLD - news) , plus high street banks Royal Bank of Scotland (LSE: RBS.L - news) , HSBC and Lloyds.
Sky (Frankfurt: 893517 - news) , the owner of Sky News, said: "It is clearly unacceptable for ads to be appearing alongside inappropriate content and we are talking with Google to understand what they are doing to stop this."
Mr Brittin said Google already spent millions of dollars and employed thousands of people to try to ensure "bad advertising doesn't get through" and that this worked well "in the vast majority of cases".
But he acknowledged it could improve and said a review which had been going on "for some time" was being accelerated.
He said Google was looking at better defining hate speech and inflammatory content, simplifying controls available to advertisers, and going further and faster in its efforts to remove "bad content" - in the context of 400 hours of content being uploaded to YouTube every minute.
Last week, media-buying agency GroupM, part of the world's largest ad agency WPP (Frankfurt: A1J2BZ - news) , told Google to apologise to customers and advertisers who saw inappropriate content on YouTube.
It has also written to clients explaining the potential risks to their brands and asking them how they want to respond.
Google was summoned to appear in front of Cabinet Office ministers on Friday.
Sky News understands the company apologised to senior civil servants representing the Government and pledged a review of their advertising systems.
Google was asked to return for another meeting this week to set out the action they plan to take.
Yvette Cooper MP, chair of the Home Affairs Select Committee, has said Google's failure to remove the hate videos by was "frankly astonishing"
Last week the committee summoned bosses from Google, Facebook (NasdaqGS: FB - news) and Twitter (Frankfurt: A1W6XZ - news) , to question them about the action the web giants were taking to remove hate speech from their platforms.