“The reason for the arrest is not clear,” said the lawyer, Alessandro Russo, in a video interview with the Corriere dell’Umbria newspaper.
“Apparently it is something to do with Facebook content, but we do not have the charge.”
Sharif was born in Egypt but has Italian citizenship and lives in the central Italian city of Terni.
Russo said he was with his mother when he was arrested.
“He was stopped by the authorities and held a long time in offices,” Russo explained.
“Then the mother saw him come out with handcuffs on his wrists.
“Upon his arrival, his Italian passport was seized and the arrest procedures were done using only the Egyptian one.”
The lawyer said Sharif was initially taken to prison in Cairo.
“He was there for a few days, in inhuman conditions,” Russo said.
“He couldn’t sleep, he could only lie down for half an hour.
“The mother saw him only once for just a few minutes.”
The woman was subsequently told that her son had been transferred to a prison in Alexandria.
The Italian foreign ministry is following the case closely.
Giulio Regeni, a 28-year-old Italian Cambridge university doctoral researcher into Cairo street unions, was allegedly tortured to death in 2016 after being detained in Egypt.
Four Egyptian intelligence officers are on trial in absentia in Rome for the homicide.
ANSA