A Lebanese judge froze the assets of five top banks and members of their boards while she investigates transactions they undertook with the country's central bank, a judicial document showed on Monday.

The asset freeze against Bank of Beirut, Bank Audi, SGBL, Blom Bank and Bankmed applies to properties, vehicles and shares in companies owned by the banks or the members of their boards.

She has not charged any of the parties mentioned with any crime.

Lebanon's banks association in statement said the decision by Judge Ghada Aoun was "illegal" and would further destabilise the country's banking system, already crippled by a financial meltdown that has seen most depositors locked out of their hard currency accounts.

Raya Hassan, chairman of the board of Bankmed, declined to comment, as did Blom Bank chairman Saad Azhari and a spokesperson for Bank Audi.

Bank of Beirut and SGBL did not immediately respond to requests for comment.

Judge Ghada Aoun on Thursday issued travel bans against the heads of the boards of the five Lebanese banks as a precautionary measure while she carried out her probe, she told Reuters. (Reuters)

•PHOTO:A general view shows the headquarters of the Lebanese Blom Bank in Beirut, Lebanon July 9, 2018. REUTERS/Mohamed Azakir/File Photo