Television viewers were stunned when a sex scene scene appeared in the background during a news debate last night.
A naked blonde-haired woman could be seen on a studio TV screen as Ed Miliband's leadership of the Labour Party was debated on Scotland Tonight.
The raunchy clip - which appeared on STV - is thought to have been from an episode of Channel 4 drama Shameless.
The image appeared on screen for a few seconds as host John MacKay questioned political blogger Dan Hodges.
Mr Hodges was in ITN's London studio when the naked woman appeared on the screen behind him after the watershed. Shadow Scotland Office Minister Willie Bain was also involved in the debate.
Today the broadcaster was forced to apologise for the mistake after viewer Paul Traynor made a formal complaint.
An insider told the Daily Record that no one in the newsroom realised the blunder had happened until they watched the footage back.
'It's unfortunate but in a busy newsroom we have monitors showing the various TV channels. You can only see the scene for a few seconds and the vast majority of viewers probably won't even have spotted it,' he said.
'However, it was probably a bit of a distraction and not exactly what they expected to see on Scotland Tonight.
'The show was on after the watershed but we will try not to let it happen again.'
A spokesman for STV said: 'We hope viewers weren't too distracted by the unexpected and incidental content on the show.'