Lebanon's Beirut port explosion judge suspends ex-PM summons
"Bitar was informed of the lawsuit against him, and suspended the questioning that was scheduled for today," a judicial source told AFP on condition of anonymity.
Diab was prime minister at the time of the explosion, and is among the senior officials Bitar wants to hear as part of his investigation.
Diab's defence team launched a lawsuit arguing Bitar does not have the authority to interrogate him.
Lebanon's political heavyweights have all denied responsibility for the country's worst peacetime disaster, but have also pulled every trick in the book to dodge Bitar's questions.
Former interior minister Nohad Machnouk, who was also handed a summons, made the same move to avoid questioning, leaving the investigation in limbo once again, the judicial official said.
Several of Lebanon's main political groups, including the powerful Iran-backed Hezbollah, want Bitar removed.
Rights groups and legal watchdogs have accused the entire political class of systematically obstructing justice.