Sky News host Chris Smith will not appear on air on Sunday evening and has been suspended from the broadcaster and his radio network 2GB indefinitely, pending an investigation into allegations of misconduct after a Christmas party over the weekend.

Smith was stood down immediately on Saturday over allegedly making lewd comments and other inappropriate behaviour at an after-party event at The Establishment in Sydney, according to multiple media sources who requested anonymity to speak freely. Smith, who is also a radio host on 2GB, will not fill in for breakfast host Ben Fordham (who is on leave) from Monday.

The media sources said concerns about the behaviour, which allegedly involved touching a young, female colleague as well a series of inappropriate comments, were raised with senior members of the Sky News executive team. The concerns were dealt with immediately.

Smith attended the Sky News Christmas Party in the Ivy Sunroom, before heading to the Establishment with other colleagues. He was seen leaving the city at about 7.30pm.

“The person involved has been suspended while an investigation into the allegations is undertaken,” a Sky News Australia spokesperson said. “The welfare of our staff is our absolute priority. We have a zero-tolerance approach to inappropriate conduct and take these allegations very seriously.”

Smith, who is also a radio host on 2GB Weekends, runs Sky News’ Chris Smith Tonight on Sundays at 6pm and was expected to become the host of a program at 5pm weeknights from 2023. He was among the crowd who attended Lachlan Murdoch’s Christmas Party on Thursday evening.

A 2GB spokesperson said Smith would not appear on air.

“2GB has been made aware of serious allegations against Chris Smith, arising from the Sky News Christmas party. Sky has advised they are conducting an investigation. Chris has been stood down from his duties at 2GB until the investigation has concluded,” the spokesperson said.

Smith has behaved poorly at a Christmas party on a previous occasion.