The Director General of Beirut Customs, Badri Daher, has been arrested as part of an investigation into the massive explosion which rocked the Lebanese capital on 4 August.
Daher, who was detained days after the blast, was questioned for four and a half hours yesterday before a warrant for his arrest was issued. The customs chief's arrest is the first since the investigation into the massive explosion was launched.
The judicial investigator on the case, Judge Fadi Sawwan, is now expected to question Director General of Beirut port, Hassan Qureitem.
Sawwan has a further 23 people, among them former and current ministers, who are named in the lawsuit to question, local daily Naharnet reported.
However, Sawwan's jurisdiction to investigate extends to "anyone identified by the investigation as being a perpetrator, partner, interferer or negligent" in the explosion, according to the lawsuit.
The judge has reportedly already visited the site of the explosion to inspect the area and assess damages.
According to President Michel Aoun, the investigation is set to be conducted in sections and aims to establish three key points: the circumstances surrounding the cargo; where the ammonium nitrate came from and who shipped it; and to find those responsibly for handling and securing it in Beirut.
The explosion happened when 2,750 tonnes of ammonium nitrate, stored unsafely in Beirut port's warehouse 12 for six years prior to the explosion, ignited. Nearly 200 people were killed in the blast which injured thousands more and made at least 300,000 of Beirut residents homeless.
In the aftermath of the blast, letters written by Daher and sent to Lebanon's "judge of urgent matters" were unearthed, detailing how the custom chief was aware the highly explosive substance was stored unsafely in the port.
In letters sent in 2014, 2015, 2016 and 2017, Daher warned of the "dangers if the materials remain where they are affecting the safety of (port) employees", according to the Associated Press (AP).
It was later revealed both Aoun and caretaker Prime Minister Hassan Diab were warned by security officials the dangerous substance was stored in the port but failed to take action.
In a secret letter to the pair sent on 20 July, Aoun and Diab were warned of the security risk the chemical posed. The pair admitted they knew the substance was stored in the port but claimed the port was not under their authority when asked why they took no preventative action.