The office of Egypt's prosecutor-general announced on Thursday that it was looking into the recent arrest of an individual accused of belonging to the proscribed 'Black Bloc' group in a building overlooking Cairo's Tahrir Square.
The prosecutor-general's office said the suspect was carrying out an "Israeli plot" targeting petrol companies in Egypt and other vital institutions.
The alleged plotters possessed maps and instructions to torch several sites, according to a report issued by the prosecutor-general, which added that the suspect is currently being interrogated by Egypt's Supreme State Security apparatus.
The prosecutor-general's office said the suspect faced charges of belonging to an illegal organisation and committing acts of sabotage.
Prosecutor-General Talaat Abdallah on Tuesday ordered the arrest of all members of the Black Bloc group, which first emerged during recent anti-government rallies during which it disrupted traffic and Cairo's Metro line.
Abdallah directed police and Egypt's armed forces to arrest anyone suspected of being affiliated with the group. He also urged citizens to provide any information they had about the group or its members and assist in their apprehension.
The prosecutor-general's report stated that the arrested individual had confessed to belonging to the proscribed group and that he bore a 'code-name.'
The suspect was arrested while trying to break into an empty apartment while donning the Black Bloc's trademark black uniform, including a black mask that covered his face and head, the report stated.
The Black Bloc joined Egypt's confused political scene during last week's anti-government riots and protests. In a video posted online, the group professed its adoption of violence to achieve so-called "revolutionary objectives."