The National Association for Change (NAC) has accused two police officers of assaulting a member of the committee tasked with investigating protester deaths during the Egyptian Revolution.

"This heinous act shows police behaviour has not changed [since the revolution]," the NAC said via a press statement on Thursday.

A committee member, Takadom El-Khatib, was travelling from Cairo to Qena by bus when it was stopped at a checkpoint. Two policemen entered the bus and treated the passengers in a reportedly "inappropriate" way. El-Khatib was then arrested and beaten at a police station, the statement said.

It is not yet clear what triggered the incident.

NAC said it held the interior minister responsible for the incident and vowed to submit a lawsuit to secure justice for El-Khatib. 

Mohamed ElBaradei founded the National Association for Change in 2009 to advocate for democratic change during the regime of ousted president Mubarak.