The Australian Federal Police have started an investigation into possible terror links of Momena Shoma who was arrested in Melbourne for stabbing a man in the neck on February 9.

Momena, 24, attacked the man just nine days after she had gone to Australia from Bangladesh on a student visa.

The investigators believe she was radicalised before flying to Australia. Even her younger sister Asmaul Husna alias Sumona, 22, attacked local police when they went to their house at Kazipara in Dhaka to inquire about Momena.

Both the sisters are now behind bars in Australia and Bangladesh.

“A representative of Australian police and a legion officer have held a meeting with us for updates of Momena and her sister Sumona,” Mohibul Islam Khan, deputy commissioner of the Counter Terrorism and Transnational Crime (CTTC) unit, told The Daily Star yesterday.

He added the Australian police have shared some information they have gathered by interrogating Momena and they have also shared some updates with them.

“We are now verifying some clues we have found about Momena,” he said without elaborating.

The CTTC officials believe both the sisters have been “self-radicalised” online. They have also found Momena's affiliation with at least two Bangladeshi youths who reportedly went to Syria and served for the Islamic State (IS).

Momena was supposed to marry one of the youths identified as Najibullah Ansari. He disappeared in early 2015 after sending a Facebook message to relatives: “Going to Iraq to join ISIS.”

The other youth, Gazi Kamrus Salam alias Sohan, returned from Syria in 2015 and has landed in prison, had introduced Ansari to Momena.

The counter terrorism officials said Momena and Ansari had developed a relationship and agreed to get married but could not in the face of opposition from Ansari's family.

Speaking anonymously, a CTTC high official told The Daily Star that Momena started changing after her enrolment in North South University in 2012. She might have connected to Nibras Islam, who was killed during a commando operation at a Gulshan café, he added.

An investigator said Sumona does not know much about Momena's personal life but has given clues to a third person. The suspect reportedly works in a private education institution and the police are conducting drives to arrest him.

Monirul Islam, chief of the CTTC unit, said they have a formal agreement with the Australian police and are exchanging updates of both the sisters.