ABC Alumni have condemned the Federal Police raid on the ABC Sydney head office as an outrage and an attack on media freedom.

Alumni co-convenor Matt Peacock said the raid is part of a pattern of media intimidation by the Federal Government and police, security and defence agencies.

"It's a disgraceful attack on freedom of the press that should have every Australian seriously worried," Mr Peacock said.

AFP officers during the raid on the ABC Utimo centre

Afghan Files

The raid relates to a series of 2017 stories known as the Afghan Files.

The stories, by ABC investigative journalists Dan Oakes and Sam Clark, revealed allegations of unlawful killings and misconduct by Australian special forces in Afghanistan and were based on hundreds of pages of secret Defence documents leaked to the ABC.

Mr Peacock said the raid had nothing to do with protecting Australia.

"It is all about protecting the reputations of a small group of out-of-control Rambos who are accused of breaking international law and have sullied the otherwise good name of the Australian Defence forces.

"The timing of this raid is also significant, coming some two years after the stories were published. It is clearly designed to intimidate good journalism. What else are they hiding?"