A pair of Indonesian pilots with alleged links to ISIS could be a major security threat, according to Australian terror cops.

A leaked Australian Federal Police report from March names Ridwan Agustin and Tommy Abu Alfatih as a terror threat because of pro-ISIS posts on their Facebook accounts.

In September Agustin, a former AirAsia pilot, started making contact with foreign fighters, such as militant Heri Kustyanto, and following pro-ISIS pages showing graphic executions, according to the report.

The second pilot is Abu Alfatih, whose Facebook profile says he was employed by airline Premiair, an aviation company that specialises in charter and VIP flights, until June 1 and is in Indonesia, also began posting in support of ISIS in December, the report added.

The report, titled ‘Identification of Indonesian pilots with possible extremist persuasions’ was obtained by US website The Intercept.

It states: “Both appear to be influenced by pro-ISIS elements including extremist online propaganda by well-known radical Indonesia outlets and a suspected foreign terrorist fighter who is likely to be either in Syria or Iraq.”

Chillingly, the report warns that the terror group is encouraging 'attacks in the aviation environment'.

It added: "Pilots, air crew and others with access to and within the aviation environment can pose obvious threats if these persons are radicalised,” the report says.

“Their access and knowledge of security and safety regimes provides the ability to attempt attacks as witnessed by past global events.

"It is noted that a recent edition of the al-Qaeda magazine Inspire actively encouraged attacks within the aviation environment.”

As of March, Agustin, under a suspected nom de plume Hobi Panahan, has listed his current city as Raqqa, the ISIS stronghold in Syria, it was stated.

The report says he uses phrases common to extremists, such as calling police 'ansharu thagut', roughly translated as 'helpers of the oppressive government'.

The whereabouts of his wife, Diah Suci Wulandari, who was also an AirAsia employee, and also shared posts from groups supporting ISIS, is unknown.

Australian Federal Police would not comment on the report.

A spokesperson said: “The AFP does not comment on matters of intelligence.

“The AFP maintains strong relationships with its domestic and foreign law enforcement partners to ensure the ongoing safety of Australians both within Australia and abroad,” the spokesperson added.

AirAsia spokesperson Audrey Petriny would only tell The Intercept: “Ridwan Agustin and Diah Suci Wulandari are no longer employees of AirAsia Indonesia.

"Therefore, we are unable to comment further on either individuals.”

Premiair said that Alfitah stopped working for the company in June.