Lebanon's caretaker prime minister was charged yesterday with criminal negligence causing hundreds of deaths over the 4 August Beirut blast.
Hassan Diab, who served as Lebanon's prime minister for barely eight months before resigning in the wake of the explosion, was charged alongside three former ministers.
They include ex-ministers of public works and transportation, Ghazi Zaiter and Yussef Fenianos, and former finance minister, Ali Hassan Khalil.
The four are the most senior officials to be charged in the investigation and are set to face questioning by lead judge Fadi Sawwan next week.
More than 200 people were killed and thousands more wounded in the August blast which was caused when 2,750 tonnes of highly explosive ammonium nitrate ignited and exploded.
Diab's office said the caretaker prime minister had a "clear conscience" and "clean hands" over the explosion.
A statement claimed Diab had dealt transparently with the investigation and said he was surprised to be targeted in the probe.
The caretaker prime minister has already given evidence in the case, as a witness, and has told the judge he has nothing to add to the statement, the Financial Times reported.
Sawwan had faced mounting criticism over the slow pace of the investigation and the failure to hold perpetrators to account more than four months after the blast.
Protests restarted in Beirut following the disaster, which many saw as the culmination of political negligence and mismanagement.
The charges against Diab, however, have been widely rejected as an attempt to scapegoat the incumbent prime minister, rather than tackle the root of the problem.
Documents unearthed in the days after the blast showed senior officials, including Lebanese President Michel Aoun, knew the chemical cache was stored unsafely in the port.
Both Diab and Aoun admitted to receiving a report about the ammonium nitrate in the port about two weeks before the explosion.
The pair each claimed to have passed the information on and ordered the removal of the substance.
Senior politicians had been repeatedly warned over the danger the substance posed but successive governments failed to remove the chemical from the port. Nevertheless, no other prime minister has yet been charged.