The judge investigating the August 2020 blast at the port of Beirut Monday postponed a questioning session of former Prime Minister Hassan Diab until Oct. 4, a judicial source told The Daily Star.

Diab had been ordered to appear at Beirut's main courthouse Monday for questioning into his potential culpability in the explosion, after Judge Tarek Bitar issued a new subpoena for him on Sept. 14. It later emerged that Diab left Lebanon for the United States the day that subpoena was issued. His adviser, Laila Hatoum, told the Associated Press that this had been a pre-planned trip in order for Diab to visit his children, who are studying in the US.

Diab was prime minister at the time of the Beirut Port explosion, which killed over 200 people and devastated the capital. In the aftermath of the disaster he and his Cabinet resigned, and to date, not a single person has been held responsible for the explosion, which is believed to have been caused by the improper storage of volatile ammonium nitrate.

The investigation into the explosion has been repeatedly stalled. Bitar's predecessor was removed from his post by a court after he attempted to charge Diab and three other ministers with "negligence and causing death to hundreds" back in February.

The former prime minister has consistently denied allegations against him, and believes that judges are violating Lebanese law, which he holds states that government officials can only be summoned to court with the prior approval of Parliament.