Police are investigating if the teen gunman who allegedly killed a police employee on Friday visited a mosque on the way to the the attack, according to reports.

Reports on Sunday indicated Farhad Jabar Khali Mohammad, 15, heard a lecture by the extremist group Hizb ut-Tahrir at a mosque, before he killed Curtis Cheng, according to Fairfax. 

Authorities are also trying to identify how the boy was supplied or came to be in possession of the firearm. 

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Police have said the teen was politically motivated to carry out the attack. 

It is believed Farhad attended Parramatta Mosque a few blocks away before changing into black robes and heading to police headquarters on Friday afternoon.

The controversial group that is considered a terrorist organisation in some countries, but not Australia, has dismissed links to the attack as just “speculation”.

“Any links are speculation and we could caution against making speculation,” a spokesperson told Fairfax. 

A senior figure at the Parramatta mosque confirmed that police searched the mosque to look for a black backpack which they believe Farhad used to carry the gun he used to kill Mr Cheng.

Police said the warrant was undertaken by arrangement with leadership at the mosque, who gave their full assistance to police.

Police also searched Farhad’s North Parramatta home and confiscated computer equipment.

The gunman has been linked to an Islamist group already under investigation. http://t.co/MitOO7vBxV #7News http://t.co/TYkMqF93HR

— 7 News Sydney (@7NewsSydney) October 4, 2015

The family of Mr Cheng, 58, have released a statement thanking NSW Police and the wider community for their support after the loss of “a kind, gentle and loving father”.

“To the many people who have offered their condolences and kind words about [Mr Cheng], we are extremely moved by your thoughts and sympathies,” the statement said.

“We are touched by the personal visit from the New South Wales Premier and the police commissioner.

“This was a comforting reminder of the warm regard that was held for him, especially by the New South Wales police community.”

Seven News knocked on the door of Ismail Al-Wahwah, a figure from the controversial group, who tried to usher a reporter away.

“The people pay to you to tell Australia, say the truth not to fabricate lies,” Mr Al-Wahwah said.

There is no confirmation as to whether the 15-year-old was a member of the group.

– with ABC