Seven West Media chief executive and managing director James Warburton has stepped down from the top job effective immediately.

His term as chief executive is coming to an end earlier than expected, with the broadcaster announcing on December 7,  that Mr Warburton would finish up "on or before" June 30.

The announcement comes after former Spotlight producer Taylor Auerbach gave evidence in Bruce Lehrmann's defamation case against Network Ten and journalist Lisa Wilkinson. 

The federal court heard allegations the Seven Network paid for illicit drugs and sex workers for Mr Lehrmann in order to secure an exclusive interview.

In a statement issued after the court hearing on April 4, a spokesman for the Seven Network said it was appalled" by the allegations made.

"Seven did not reimburse Bruce Lehrmann for expenditure that has allegedly been used to pay for illegal drugs or prostitutes, and has never done so," the statement said.

On Wednesday it was announced the student falsely accused by Channel 7 News as the perpetrator behind the Bondi Junction stabbing that left six people dead would pursue legal action against the network.

A 7 News spokesperson told the ABC the "mistake was human error and it has been rectified" and that "Seven sincerely apologises for the error".

The network has 28 days to respond to the defamation claim.

Seven's chief financial officer Jeff Howard will take on the role of CEO from Friday. 

In a statement, Seven West Media said Mr Warburton would finish at the broadcaster on Thursday. 

It said chairman Kerry Stokes and Mr Howard had both thanked Mr Warburton "for his contribution to the business over many years". 

Craig Haskins has been appointed as acting CFO until a successor for Mr Howard can be announced, Seven West Media said.