By Andrew Brown in Canberra

Social media companies remain reluctant to allow Australian authorities access to encrypted messages in investigating extremist groups despite repeated pleas, the head of the domestic spy agency says.

ASIO director Mike Burgess told a parliamentary inquiry into right-wing extremism that despite calls to tech platforms to assist the agency in investigations, changes have not been made to how encrypted messages are accessed.

The comments came after Mr Burgess used an address to the National Press Club in April urging social media platforms to co-operate.

“We continue to want to, and in some cases do, have those conversations with industry partners, but we’re making little progress,” Mr Burgess told the inquiry on Wednesday.

“My plea to industry is there, under law, we need your assistance, and we want to have those conversations… we’ll continue to push in hard to our industry partners.”

Mr Burgess said the appeals to social media companies would not mean ASIO would have access to everyone’s conversations.

Instead they would apply to individuals under investigation in a “limited set of circumstances”.

“These are violent extremists who, one day, one of them will likely kill someone, and come the coronal inquiry or the police investigation, we will discover we were unable to get in there and get that intelligence,” he said.

“That is going to be a hard day. I don’t think that day’s too far away, so we’re asking for help.”

The inquiry has been told unregulated social media platforms help promote and fund extremist groups including white supremacists.

ASIO said right-wing extremism was an increasing threat with concerns young people were being radicalised.

“I’m deeply concerned that we are seeing young Australians, some barely in their teens, hanging Nazi flags and portraits of the Christchurch killer on their bedroom walls,” Mr Burgess said.

“In recent months, there have been several disturbing incidents involving minors who may adhere to nationalist and racist violent ideologies.”