Security sources said Zahar, who was returning to the Palestinian territories after a tour of Arab and Islamic countries, crossed the Rafah border with the money in a suitcase on Tuesday.
Palestinian officials have resorted to carrying cash into the territories after Western donors cut financial aid when Hamas took the helm of the Palestinian government in March, leaving tens of thousands of civil servants without pay in months.
Güncelleme Tarihi: 20 Eylül 2018, 18:16
Western countries have demanded that Hamas renounce violence and recognise Israel's right to exist as a condition for lifting the boycott.
Earlier this month, Arab foreign ministers vowed to ignore the aid freeze imposed on the Palestinian Authority and start stepping up payments.
Israel withdrew its troops from the border a year ago following a deal tasking the European Union with monitoring the Rafah crossing.
But Israel has complained of arms smuggling and imposed frequent closures.