BEIRUT - French judges visiting Beirut this week as part of an investigation into a massive port explosion in 2020 were denied access to documents from the Lebanese probe because it remains frozen, a senior Lebanese judicial source said on Thursday.

The Lebanese investigation into the explosion that killed 220 people and shattered Beirut has been frozen for a year, derailed by political resistance from ruling factions and legal challenges against the lead investigator Judge Tarek Bitar.

The two French judges were in Beirut as part of an investigation opened by the French prosecutor's office because there were French nationals among the casualties, including two dead, a French diplomatic source said.

Bitar told the visiting judges he was unable to share information until he was allowed to resume his inquiry, the source said. He would be able share information not governed by secrecy rules once the probe resumed, the Lebanese source added.

Reuters could not reach the judges for comment.

The explosion, one of the most powerful non-nuclear blasts on record, was caused by hundreds of tonnes of ammonium nitrate unloaded at the port in 2013.

Lebanese efforts to investigate the explosion have encountered strong political pushback.

IN LIMBO

Bitar has sought to question senior politicians, including members of Parliament Speaker Nabih Berri's Amal Movement, Hassan Diab - prime minister at the time of the blast - and top security official Major-General Abbas Ibrahim.

All of them, including former ministers Ali Hassan Khalil and Ghazi Zeaiter, have denied wrongdoing and said Bitar does not have the power to quiz them, arguing they have immunity.

The probe has been in complete limbo since early 2022 due to the retirement of judges from a court that must rule on several complaints against Bitar, submitted by officials he has sought to question, before he can continue.

The powerful Shi'ite group Hezbollah, several of whose allies are among those Bitar wants to question, has also opposed him.

A top Hezbollah official said in 2021 the group would remove Bitar from the probe, while Hezbollah's leader Sayyed Hassan Nasrallah said was biased and should be replaced.

The court of cassation removed Bitar's predecessor, Judge Fadi Sawan, in 2021 following high-level political pressure.

The Lebanese source said the French judges asked about the delay and when the probe would resume.

The French judges also met lawyers representing families of the victims, who are campaigning for accountability, said Cecile Roukoz, one of the lawyers.

(Reporting by Laila Bassam; Writing by Tom Perry; Editing by Alex Richardson)