Wissam Tarif, a Lebanese national who works for Avaaz, an online activism network, arrived in Egypt on Tuesday morning and was deported that evening, Avaaz spokesman Sam Barratt said.
Tarif intended to present the petition to Egypt's top Islamic official, Mufi Shawki Ibrahim Abdel-Karim, yesterday, Barratt said. Under Egyptian law, the official must approve all death sentences before they can be carried out.
Tarif arrived yesterday at Cairo's international airport, where officials detained him at passport control because his name was on a watch list, an airport official said. The official spoke on the condition of anonymity because he was not authorized to speak to journalists.
"In Egypt today, peacefully delivering a massive petition to a religious leader is deemed a threat to national security," Tarif said in a statement. "They tried to silence 1 million voices with my deportation, but our campaign will now intensify."
A court sentenced the 529 to death on March 24 for an attack on a police station that killed a police officer, convicting them after only two hearings in a mass trial that activists criticized.
Though lawyers say the verdicts are subject to appeal and likely will be overturned, the swift ruling has raised concerns that the country's courts are becoming politicized in the wake of the July 3 overthrow of President Mohammed Morsi and a subsequent crackdown on his Muslim Brotherhood group.
Youssof Salahen, a spokesman for a student group supporting Morsi, said that security forces fired birdshot and tear gas into the funeral for high school student Hossam Salama, killed by a gunshot wound to the head after clashes at Cairo University earlier this week.