Officials of the Scottish Parliament are now investigating the cause for pornographic advertisements to suddenly pop up on the parliament's TV system.

Advertisements for adult channels such as Red Hot Wives, Playboy TV and Spice Extreme began popping up on 320 TV monitors at Holyrood.

Though they could not be accessed, the porn channels appear on the list of channels on Holyrood's TV system.

A spokesperson for Holyrood said the channel labels might have been added by mistake to the TV feed and that the supplier, Telewest had already been asked to remove them.

"The channels have been removed," the spokeswoman said. "There is no way anybody could watch porn in parliament."