BEIRUT, Oct 12 (Reuters) - A probe into the catastrophic Beirut port explosion was suspended on Tuesday for the second time in less than three weeks after two politicians wanted for questioning filed a new complaint against the lead investigator, Judge Tarek Bitar. The investigation has been facing obstacles since Bitar sought to question some of the most powerful people in Lebanon on suspicion they were aware of the stored chemicals involved in the blast but had done nothing to avert the disaster. Bitar has been under enormous pressure from groups that have accused his probe of political bias and mounted a smear campaign against him. The leader of the powerful, heavily armed Shi"ite political movement Hezbollah said on Monday it wanted Bitar removed from the case. In a cabinet meeting on Tuesday, ministers, mostly from Hezbollah and the Amal Shi"ite movement, pushed for Bitar"s removal in a heated discussion that was left unresolved, two sources with direct knowledge of the matter said. The government is due to meet again on Wednesday. The Aug. 4, 2020 blast, one of the biggest non-nuclear explosions on record, killed more than 200 people and devastated swathes of Beirut. Senior officials from across the political spectrum have refused to show up for questioning and arrest warrants are now unlikely to be executed. Bitar had wanted to interrogate them on criminal negligence charges as they had served in posts where they would have been in a position to know about the ammonium nitrate stored unsafely at the port for years. A meeting of the country"s supreme defence council, chaired by President Michel Aoun, on Tuesday refused the permission sought by the judge to pursue Tony Saliba, the director general of state security, an official source said. The probe was suspended in late September on the basis of a complaint questioning Bitar"s impartiality. A court rejected the complaint on procedural grounds, allowing him to continue. Bitar is the second judge to lead the probe. Fadi Sawan was removed from the case in February after a similar complaint filed by the politicians who are now challenging Bitar. "For the first time, the judicial system wants to function, but it is suffering under the political pressure and interventions," said Paul Morcos, lawyer and professor of international law. ARREST WARRANT Shortly before being informed of the latest complaint, Bitar had issued an arrest warrant for one of the politicians who filed it, former finance minister Ali Hassan Khalil, a senior politician close to Hezbollah. Khalil, a senior member of the Shi"ite Amal movement, was not immediately reachable for comment. The second politician was ex-public works minister Ghazi Zeiter, also a Hezbollah ally, who is due for questioning on Wednesday. Hezbollah leader Sayyed Hassan Nasrallah voiced his harshest criticism yet of Bitar on Monday when he called for his replacement in a televised address, saying he was biased and politicised. read more The remarks came weeks after Wafik Safa, a senior Hezbollah official, was said to have warned Bitar the group would remove him from the inquiry, according to a journalist and a judicial source. read more Khalil"s arrest warrant is the second for an ex-minister arising from the investigation. The first was issued for ex-public works minister Youssef Finianos, another Hezbollah ally, in September when he repeatedly failed to show for questioning. read more