Lebanon's Maronite Patriarch Beshara al-Rai called on Sunday for the judge struggling to investigate the Beirut port explosion to be able to pursue his work and get help from any outside authority to pinpoint those responsible for the devastating blast.

Long-simmering tensions over the investigation have boiled over since Judge Tarek Bitar brought charges against some of the most influential people in Lebanon, defying political pressure to scrap the inquiry into the disaster that killed 220 people.

With friends and allies of Lebanon's most powerful factions, including Hezbollah, among those charged, the establishment struck back swiftly last week when the prosecutor general charged Bitar with usurping powers.

Critics called it "a coup" against his investigation.

"We hope investigating Judge Tareq Bitar continues his work to uncover the truth and issue a decision and get help from any international authority that can help disclose the truth...," Reuters quoted Al-Rai as saying in a sermon.

The Aug. 4, 2020 blast was caused by hundreds of tons of improperly stored chemicals of which the president and prime minister at the time were aware, among other officials.

Bitar resumed his inquiry on Jan. 23 after a 13-month break caused by legal wrangling and high-level political pressure, issuing charges against a number of senior officials including top public prosecutor Ghassan Oweidat.

Oweidat rejected Bitar's move and filed charges against him for allegedly mishandling the inquiry, as well as ordering the release of people detained in connection with the blast.

Rai has long said that Lebanon's judiciary should be free of political interference and sectarian activism.

"We won't allow however long it takes and rulers change to let the crime of the port pass without punishment."