The British government has summoned the tech firm to explain itself after a newspaper investigation showed that taxpayer-funded ads were used on inappropriate content including videos from former Ku Klux Klan leader David Duke.
"We have placed a temporary restriction on our YouTube advertising pending reassurances from Google (GOOG) that government messages can be delivered in a safe and appropriate way," the British government said in a statement.
The investigation published by The Times showed that ads from the BBC, Transport for London, Visit Scotland, L'Oreal (LRLCF), the Financial Conduct Authority, Honda (HMC), supermarket chain Sainsbury's and The Guardian all appeared next to objectionable content on YouTube.
In addition to former Klan leader Duke, the ads were used alongside content from far-right party Britain First and an organization of Polish nationalists, as well as a smattering of religious extremists and controversial hate preachers.
Google said in a statement that it has "strict guidelines" that define where ads should appear.
"We accept that we don't always get it right, and that sometimes, ads appear where they should not. We're committed to doing better, and will make changes to our policies and brand controls for advertisers," it added.