Egypt's State Security Prosecution ordered on Monday the detention of activist Moheb Doss, a leading member of the anti-Morsi Tamarod group, for 15 days pending investigation on charges of joining an "outlawed group."

Doss was arrested on 6 January in front of the Saint Mark Orthodox Cathedral in Cairo Abbasiya's district, where Egyptian President Abdel-Fattah El-Sisi was giving a speech during the Coptic Christmas mass.

He has been accused of joining an outlawed group called 'January 25 Youth', his lawyer Mohamed Fadel told Ahram Online, saying the charges were false.

Doss was a leading member of the Tamarod campaign, which gathered milions of signatures in 2013 demanding that then-president Mohamed Morsi step down.

There have been several calls for anti-government protests on 25 January, the fifth anniversary of the uprising that toppled then-president Hosni Mubarak. Protesting without prior police permission is banned in Egypt, under a law passed in 2013.

"The authorities don't have any evidence against him. He wasn't given the right to contact a lawyer, or even the right to be questioned by a normal prosecution, not a specialised one," Fadel added.

According to family, his laptop was confiscated from home by authorities on 7 January.

The Kefaya movement, founded in 2004 to oppose Mubarak, condemned the arrest of Doss “without charges”, describing the wave of recent arrests made by the security forces against young activists as “frenzied.”

The movement added in a statement that the security forces has lost the sense of differentiation and were now targeting “all the icons of the January 25 uprising”, and oppressing any voice that opposes or criticises the policies of the current authorities.

The movement said that it would hold the Egyptian interior ministry fully responsible for the safety of those youth who have been arrested, calling on President El-Sisi to announce his political affiliations and true stance towards the January 25 revolution, adding that such a repressive role negatively affects the overall credibility of the regime.

Doss was the first of Tamarod's founding members to say publicly that security officials had influence over the anti-Morsi group, in an interview with Buzzfeed in 2014.

“How did we go from such a small thing, five guys trying to change Egypt, to the movement which brought tens of millions to the street to get rid of the Brotherhood? The answer is we didn’t. I understand now it wasn’t us, we were being used as the face of what something bigger than us wanted,” said Doss in the interview.

According to Doss, Tamarod founding members Mahmoud Badr, Mohamed Abd El-Aziz and Hassan Shahin met with state and army officials during Morsi's presidency, including now-president Abdel-Fattah El-Sisi, at that time head of the military. The three activists declined to comment at the time.

“I realised that they were taking orders, being used by state institutes,” Doss said in the interview, asserting that the group was no longer independent and was receiving limitless funding from the state.

Badr, once spokesperson for Tamarod and a supporter of El-Sisi's policies, was sworn in on Sunday as a member of Egypt's newly formed parliament.

While the Egyptian state has not banned Tamarod, courts banned in 2014 the 6 April group, which played a key role in fomenting the 25 January revolution, and police have  arrested and jailed many of its members since the end of 2013.