Oxfam has removed one of its adverts from YouTube after it was shown on channels showing content from extremist group ISIS.

An investigation by BBC Newsnight found that adverts by not-for-profit organisations, including Oxfam and the National Citizen Service were being shown running next to videos used to spread Islamist propaganda.

The investigation found that adverts were shown before videos encouraging young people to join the conflict in Syria, and that advertisers were potentially unwittingly funding extremists.

A spokesperson from Oxfam said: “Oxfam is extremely careful in the way it places adverts online. There are checks and systems in place to ensure that our ads only appear on videos that are aimed at potential supporters and not alongside content that is contrary to our values.

“On sites like YouTube, these decisions are made automatically and in this instance the system has led to a placement that is not acceptable. The ad has now been removed and we will work to make sure this doesn't happen again.”

YouTube told the BBC that it has removed violent videos when they were flagged by users.

Michael Lynas, chief executive of the National Citizen Service, a community interest company set up by the government to run its flagship youth volunteering programme, said: “No National Citizen Service video should appear before the sort of material Newsnight has highlighted.

“It is appalling and is entirely against the ethos of NCS, which brings young people from all backgrounds together, building a more cohesive, engaged and responsible society.”

He added that NCS immediately suspended its YouTube account while it urgently investigated the issue. The promotional material has since been removed from the video highlighted by the BBC and, although their campaign has been resumed, the situation will be kept under review.