Channel 4 has controversially blocked its own news webcasts in China and Zimbabwe, in an effort to protect its news sources in each country.

C4's assistant foreign editor of Channel 4 News, Tim Lambon, told delegates at the News Xchange 2008 conference in Valencia that its online self-censorship policy was due to concerns for the safety of its local news sources.

The Guardian reports that C4 "has taken the decision to block servers in countries where there was deemed to be a significant risk of reprisals against local people involved in making Channel 4 News reports."

CNN and NBC annoyed

Lambon also admitted that "a number of our clients, including CNN and NBC, have been quite annoyed with us when we have put restrictions on whether they can run [online] broadcasts of those pieces, those very strong pieces.

"The whole idea is to get it out there so that people can be aware of those stories, but the problem has been that if we do that we often jeopardise the people involved in actually putting together the story and who have told their stories in the piece."

Lambon stressed that (supplier of C4 news) ITN's priority was to safeguard its sources.

"There is self-censorship because you could endanger people if you put it up on the net, if you broadcast it internationally. In terms of taking care of the people that are involved British broadcasting has a very responsible attitude."