Bashar al-Assad’s former defence minister has reached Istanbul after a defection that betrays cracks in the President’s support among his own Alawite sect, opposition and diplomatic sources said yesterday.

Dismissing a cursory Syrian state TV denial of the first Reuters report that General Ali Habib had been spirited across the Turkish frontier this week, opposition figures said Habib was likely to keep a low profile after evading house arrest and reaching Turkey with the aid of Western agents.

One prominent opposition figure also spoke of speculation that Habib, who is in his 70s and apparently broke with Assad after a crackdown on protesters in 2011, might be lined up by US and Russian officials for a role in transitional arrangements to negotiate an end to the civil war.

“My information, based on a trusted Western source, is that he is in Istanbul,” veteran dissident Kamal al-Labwani, now based in Paris, said yesterday.

“[He] exited with Western intelligence involvement, so don’t expect public statements by security operatives on his whereabouts.”

A source in one of the Gulf Arab states that is backing the revolt against Assad said Habib had crossed Turkey’s southern border after dark on Tuesday and had reached Istanbul, a base for the Western-backed Syrian National Coalition.

A Western diplomatic source said he had confirmation Habib had defected and was in Turkey.

He dismissed a brief report on Syrian state TV on Wednesday that said he was still at his home.

The station has not repeated that denial and other state media have not mentioned Habib.

The Turkish government, which hosts Syrian military officers who defected, has not confirmed the general’s presence.

He has not been seen in public this week.