Sydney crime and bikie gangs are using uncrackable mobile phones to arrange murders, shootings and drug deals – hampering the ability of police to solve the crimes.

Law enforcement agencies have warned about the increased use of encrypted mobile phones, with the devices being used to arrange at least two recent murders and hampered investigations into at least two others.

The execution of Hells Angels member Tyrone Slemnik involved an encrypted phone. Credit:Wolter Peeters

Detectives from the organised crime squad this month arrested and charged a Sydney man who allegedly had 55 encrypted devices in his CBD flat. It is understood the man had up to 800 clients on his books from a range of criminal networks.

The phones with the encryption software and a US SIM card can be bought in Sydney for between $2300 and $2800 for a six-month subscription. Users can then pay upwards of $1000 to extend their subscription for another another six months.