The World: Beijing - Did government or server put video site offline?, one of the largest Chinese online video sites, has gone offline, in the course of an investigation by state officials. The site has blamed maintenance work for the disruption and has apologised to users.

However, the shutdown is said to be connected to an investigation by the State Administration of Radio, Film and Television into its content. "It's clearly serious," an insider said.

Onlookers say the extended blackout could harm's standing with users and advertisers.