JERUSALEM // Where is Mohammed Dahlan? For days rumours have swirled of a falling out between the one-time heir apparent to Yasser Arafat and the Palestinian president, Mahmoud Abbas.

Palestinian Authority officials will not confirm the reports, but what is certain is that Mr Dahlan, 49, Fatah's former security chief in the Gaza Strip, has dropped out of sight.

The Palestinian daily Al Quds Al Arabi recently reported that Mr Dahlan had openly criticised the Palestinian president and his family's business dealings.

As a result, Palestinian political observers said yesterday, Mr Dahlan has been stripped of his bodyguards and threatened with imprisonment.

These observers, who spoke on condition of anonymity because of the delicacy of the issue, said Mr Dahlan's criticism of Mr Abbas amounted to an open grab for power.

"If you want to become the big guy, you choose the biggest guy and start something with him, and Dahlan did that," one analyst in Jerusalem said. "He's become the talk of the people, which means that, in a way, he succeeded."

Nasser al Qidwa, a fellow member on Fatah's central committee, the group's executive body, would neither confirm nor deny accounts of a power struggle between the two senior figures in Palestinian political circles.

"These are internal issues that, frankly, should not be discussed with the media," Mr al Qidwa said.

The ongoing Dahlan saga is a hint of the dissent brewing inside the senior echelons of the Palestinian leadership, particularly since Mr Abbas has so far returned empty-handed from unpopular peace talks with Israel, said George Giacaman, a Palestinian political analyst and co-founder of the Palestinian Institute for the Study of Democracy.

"There are always factions within Fatah itself competing and aligning with each other," he said. "But now that things have come out this way shows there's a bit of a crisis, and it has to do with the fact that [the peace] negotiations are in crisis."

Mr Dahlan would seem poised to capitalise on Mr Abbas's failures at the negotiating table.

Whereas critics decry the Palestinian leaders' drab personality, Mr Dahlan is praised for the opposite reasons: his eloquence and charisma are widely credited for helping catapult him into senior leadership posts at a young age, most notably as head of the Palestinian Authority's security apparatus in the Gaza Strip until Hamas overran his forces there in 2007.

Although disliked by rivals for failing to thwart Hamas's takeover of Gaza, the photogenic Mr Dahlan is said to have growing support of Fatah members opposed to the current Palestinian leader and his unelected and independently minded prime minister, Salam Fayyad.

Colleagues describe Mr Dahlan as a well-organised administrator whose ability to speak Hebrew and English have made him a favourite of the Israelis and Americans.

"He surrounds himself with good people," said a fellow Fatah member who requested anonymity. "He appreciates advice. He has good advisers. You don't see too often in our leadership someone who likes to have a communications adviser."

Although lacking formal education - he learned Hebrew in Israeli prisons - his ease with foreigners allegedly helped him forge links with the CIA that many Palestinians believe endure.

Critics say Mr Dahlan is a slick self-promoter whose chief interest is his own self-aggrandisement, the prototype for an Arab strongman whose time has passed. In Gaza, he is reviled by Hamas for overseeing a security service that repressed, beat and allegedly tortured Hamas members.

His ostentatious habits have also raised questions about his finances. One Fatah official, for example, described the source of Mr Dahlan's wealth as known only by "him and God".

Whatever the source, it is enough for Mr Dahlan to afford a motorcade that those who have seen it say is only outmatched by that assigned to Mr Abbas.

Majid Shihade, a professor of international studies at Birzeit University, said: "He used to run around Ramallah with 10 cars, bodyguards.

"When he went around the city, he used to make more of a scene than others. When he visited friends, they would close off the entire street."

But his apparent attempt to one-up Mr Abbas, at least for the moment, has failed, Professor Shihade believes.

"Dahlan doesn't have that base of support, the skills, the experience," he said. "I think he just overestimated himself."