"President Abbas ordered the attorney general to open an investigation and question Sami Abu Zurhi on where this money came from," said a source in Abbas' office in the West Bank town of Ramallah.

Abu Zuhri, a Hamas spokesman, was caught trying to smuggle 639,000 euros (about 817,000 U.S. dollars) at the Rafah border crossing between Egypt and the Gaza Strip. The money was confiscated by the Palestinian customs authorities.

Abu Zuhri told the Al-Jazeera Arabic news channel that the money was donated privately by individuals he met during a tour of Arab nations.

But he did not declare the money and tried to smuggle it, said spokesman for the European Union monitors supervising the Palestinian-controlled crossing.

The spokesman said travelers crossing through Rafah must declare all sums over 2,000 dollars (euro 1,600) and explain its origin.

The Hamas-led Palestinian government has been cash-strapped since it took office in late March as the United States and the EU cut off badly needed aid to punish Hamas for its refusal to renounce violence, recognize Israel's right to exist and accept previous peace accords.