A Russian internet activist who created a popular app allowing people to send alerts over arrests by the police was Monday remanded in custody awaiting trial on charges of drug possession.

The jailing of Alexander Litreyev for at least the next two months sparked concern that he had been specifically singled out due to his activism, although he has admitted the charges.

Litreyev was detained on Sunday shortly after arriving in the Urals city of Yekaterinburg and was found to be in possession of less than a gram of ecstasy, the Interfax news agency reported.

His lawyer Alexei Bushmakov told Interfax that Litreyev had confessed his guilt and expressed remorse and was thus surprised by the court's "tough" decision to hold him for two months in jail in pre-trial detention.

His arrest comes amid growing concern among activists that the Russian authorities are using drugs charges to target campaigners behind troublesome initiatives, especially concerning the police.

Litreyev designed a special mobile phone app called Krasnaya Knopka (Red Button) that allows people to rapidly alert relatives and civil society campaigners if they are arrested in a demonstration and indicate which police station they have been taken to.

Bushmakov told the Meduza website that Litreyev had travelled to Yekaterinburg for just one day to meet a woman he had met on Instagram. The woman gave evidence in the court hearing, Meduza said.

Litreyev will now be held in prison for the next two months until the next hearing when the judge will decide again whether he stays in jail.

A date for the trial has yet to be sent. Pre-trial detention periods can be lengthy in Russia.

'Set up and framed'

The Rosuznik Russian prisoner support group said on Twitter that the jailing of a person "who has admitted his guilt on a non-serious offence is an outrage. He should be immediately released".

Video posted on Russian news sites showed Litreyev, standing in a courthouse cage, unsuccessfully trying to persuade the judge he was not a flight risk and should not go to jail ahead of trial.

Meduza said the expert in data security had previously worked with the anti-corruption group of Russian opposition leader Alexei Navalny.

Litreyev was "specially lured, set up and framed. A honey trap, straight out of the text book," Navalny wrote on Twitter.

However some Russian news sites carried interviews with the woman he had met, reportedly aged 19, in which she vehemently denied setting up Litreyev and complaining she had been the victim of attacks on social media since the news broke.

She said she had been detained with him before being released.

Litreyev, who is based in Estonia, also heads a company called Vee Security which offers VPN connections allowing Russian users to see sites blocked in Russia.

Arrests by Russian police of activists on suspicion of possessing drugs have been in the spotlight since reporter Ivan Golunov was detained on trumped-up drug charges last June.

Five former police officers have been detained for planting drugs in Golunov's backpack and at his flat.

He was released after an unprecedented public campaign in his defence by supporters.

Kremlin critics say drugs charges are routinely used in Russia to silence rights activists or to settle scores with opponents in disputes.

Russia Instagram Criminal Law