Teen jail-bird taunts police on Facebook

The teen has posted pictures of himself brandishing a rifle on Facebook. Photo / AP

A 17-year-old escapee has taunted Australian police on Facebook but is under increasing stress and showing false bravado, a senior officer says.

The teenager has posted comments about his escape on a social media site, with friends calling him "famous" and urging him to be careful.

Under one screenshot of a media report of the case, he posted the comment, "how about that" while another picture showed him brandishing a rifle.

Chief Inspector Alby Quinn said police believed the Facebook page was genuine and were using it as part of the hunt for the youth, who escaped on Monday.

He said information received from the public suggested the teenager was under increasing stress and had possibly shaved his head to change his appearance.

"I'm sure there are people out there within his close group who are assisting him at this stage," Chief Insp Quinn said on Thursday.

"The bravado he's shown on Facebook, we believe is actually a false form of bravado and that's basically because we do believe he's under increasing stress."

The teenager has been on the run since eight youths, aged 16 to 19, used a hacksaw blade to cut their way through a security fence at the Cavan Training Centre in Adelaide on Monday night.

The seven others were caught within 24 hours.

An investigation has been launched into the circumstances of the escape, with a final report due by March 23.

Premier Jay Weatherill said he was concerned about the escape and the public had a right to expect such incidents would not occur.

Cavan is a centre for male youths who have been convicted and detained or who are on remand until their court matters are finalised.

- AAP