BRAZEN: Lembo's gang smuggled cocaine on a private jet
CRIMINALS are trying to out-fox investigators by using high-tech mobile phone systems that leave no traces of messages and contacts.
New privacy guards on some operating systems mean that even investigators from the National Crime Agency (NCA) - often described as Britain's FBI - cannot retrieve deleted messages or contacts lists.
Forensically restoring deleted communications on suspects' phones has been pivotal to securing several convictions involving organised criminals who have used mobile phones to communicate with each other.
JAILED: Lembo was convicted but was able to keep phone communications from NCA investigators
But the NCA has admitted there are some phones now so sophisticated it has been unable to retrieve the data.
Steve McIntyre, NCA senior investigations manager, said one of the phones had frustrated a recent cocaine smuggling investigation.
Alessandro Lembo, 28, from Bournemouth was arrested with others as part of a probe into an attempt to smuggle half a tonne of cocaine worth £41 million on a private jet from Colombia into Farnborough Airport in Hampshire.
But NCA investigators were unable to get anything of use from his phone due to its high security settings.
PRIVATE: Lembo used a BQ phone with special security settings
Mr McIntyre said: "Lembo was using a special BQ phone. You can set false partitions in it. The communications cannot be recovered. We were not able to recover anything forensically."
Lembo and three others were jailed for a total of 92 years at Woolwich Crown Court, but only because they were caught red-handed with the drugs in their bags at the airport.
Mr McIntyre said they were unable to retrieve any potential messages with criminals higher up the phone from Lembo's phone because of the settings, and the phones were likely to frustrate future investigations where mobile phone evidence may be more crucial.