Mushir al-Masri was stopped from crossing late on Tuesday pending the "co-ordination" required to transfer the two million dollars he was carrying into the Gaza Strip, the official told AFP on condition of anonymity.
Another Hamas deputy, Ahmed Attiya Bahr, who was carrying the same amount, was also given the green light to cross the Gaza border, the official said.
Masri "informed the Egyptian side that he received this money, which is aid for the Palestinians, after a trip to Saudi Arabia", according to the Egyptian source.
Israel withdrew its troops from the border a year ago following a deal tasking the European Union with monitoring the Rafah crossing. But the Jewish state has complained of arms smuggling and imposed frequent closures.
Arab foreign ministers on Sunday vowed to ignore the aid freeze imposed on the Palestinian Authority.

Copyright AFP (Agence France-Presse), 2006