Three photojournalists have been detained on charges of spreading false information after conducting interviews on the streets with members of the public in central Cairo, officials said on Sunday.

The trio were arrested on 26 September and remanded in custody for 15 days, according to a security official and a member of the Egyptian journalists' union.

Their lawyer, Fatma Serag, told AFP the three had been "beaten and electrocuted" while in detention and accused of "belonging to an illegal organisation" and "spreading false news".

Rights groups say President Abdel Fattah al-Sisi's government has tried to repress all opposition since the former army chief overthrew his predecessor Mohamed Morsi in 2013.

Journalists Ossama al-Bishbishi, Mohamed Hassan and Hamdy Mokhtar - all Egyptian - "were conducting interviews with passers-by near the Journalists' Syndicate," union official Khaled Elbalshy told AFP.

Serag said they were accused of "using recording devices to spread false information through television channels in Turkey giving a bad impression of Egypt".

A number of members of Morsi's blacklisted Muslim Brotherhood have sought refuge in Turkey as relations between Cairo and Ankara deteriorated since the overthrow of Egypt's first democratically elected leader.

Serag said the journalists were filming a segment on Islamic clothing when a passer-by informed the police.

The security official said the three men had been filming without the necessary permit.

Police in May raided the Journalists' Syndicate and arrested two reporters accused of "inciting protests" against the authorities.

Elbalshy himself currently faces charges of harbouring wanted men in the union headquarters.

Photographer Mahmoud Abdel Shakour has been detained for three years after being arrested while covering the police dispersal of a protest camp in Cairo in August 2013.