Police want a teenager previously linked to an Anzac Day terrorist plot released on bail because they believe there is a risk he could become radicalised in prison.

Commonwealth prosecutor Andrew Doyle told the County Court on Thursday that while Afghan refugee Mehran Azami, 19, of Narre Warren, had tried to import more than 300 potentially deadly weapons into Australia, he did not know about the alleged planned Anzac Day attack.

AK-47 flick knives found online.

Mr Doyle said police only became aware of Azami from intercepted phone calls in which he agreed to supply Harun Causevic with a Cold Steel AK-47 flick knife.

Azami was arrested in April with Causevic and Sevdet Besim, both 18, who were both initially charged with conspiring to prepare for, or plan, a terror attack.