A Lebanese court ordered on Thursday the temporary seizure of property owned by two parliamentarians charged in connection with the deadly Beirut port blast of 2020, a judicial source said.

Property worth about $3 million is to be confiscated under the order, which will be formally communicated to MPs Ghazi Zeaiter and Ali Hassan Khalil, charged in December 2020 over the explosion that killed more than 220 people four months earlier.

The exact charges have not been made public as the investigations are classified, but both MPs deny any wrongdoing and have declined to attend interrogation hearings, citing immunity as members of parliament.

Lebanon's blast investigation has been stalled since late 2021 because of a slew of counter-motions issued against the investigating judge.

Both Zeaiter and Khalil were re-elected in the May 2022 elections, to the dismay of families of the victims.

"This complaint was filed originally by victims of the blast, who claimed that the two parliamentarians had abused their power in filing motions to slow down the probe," the judicial source told Reuters.

"The amount is meant to represent a sort of compensation. It's the first time I've seen such a complaint filed in a Lebanese court," the source said.

Rumors of the decision late on Wednesday prompted a statement by lawyers for the pair on Khalil's Twitter account, calling the move a "violation" of legal norms.

"Once we are formally informed, we will present a list of answers responding to the allegations and fallacies of the accusing side and (requesting) the seizure be lifted," they said.

Mariana Fadoulian, who lost her sister in the blast, is among the 10 families who filed the complaint this year.

"We know this won't mean the probe is back on, but it's a first step. Now they know that we haven't forgotten them and they're not above the law," Fadoulian told Reuters.

"What we really want is a full amendment of the law that means such complaints by the accused won't stop an investigation."