A Lebanese judge Monday issued an arrest warrant for ex-central bank chief Riad Salameh, a judicial official said, after the detained former official was questioned in an embezzlement case.

Salameh, 75, is accused of amassing a fortune during some three decades in the job and faces numerous charges, including embezzlement, money laundering and tax evasion in separate probes in Lebanon and abroad.

He has repeatedly denied any wrongdoing.

The investigating judge questioned Salameh for two and a half hours and "issued an arrest warrant against him", the official told AFP, requesting anonymity as they were not authorised to brief the media.

The judge scheduled another hearing Thursday to continue questioning Salameh, the official added.

On Tuesday last week, Lebanese authorities for the first time provisionally arrested the embattled former official after he was questioned over the alleged embezzlement of more than $40 million, another judicial had told AFP.

The official said at the time that the case was "completely separate" from others being investigated.

The following day, Lebanon's financial prosecutor initiated legal proceedings against Salameh over allegations of "embezzling" public funds, as well as "illicit enrichment and money laundering", and the case was referred to the investigating judge, the same official told AFP.

In a statement Friday carried by Lebanon's official National News Agency, Salameh's office said he had cooperated with the Lebanese judiciary "before and after finishing his official duties" and "has continued with this cooperation since his detention".

Salameh, who also has French nationality, is widely viewed as a key culprit in Lebanon's economic crash which began in late 2019 and which the World Bank has called one of the worst in recent history.

A handful of protesters gathered outside Beirut's justice palace, some trying to attack a convoy of vehicles transporting Salameh as he arrived, hitting the windows and yelling "criminal", an AFP correspondent said.

"No to your corruption, conspiracy, indifference, yes to justice," one of the protest signs read.

In May last year, Germany and France issued arrest warrants for Salameh over accusations including money laundering and fraud, though German prosecutors later cancelled their warrant, saying Salameh could no longer use his post to suppress evidence.

In August last year, the United States announced coordinated sanctions with Canada and Britain against Salameh.

The former official has repeatedly said his wealth comes from private investment and his previous work at US investment firm Merrill Lynch.

He has defended his legacy, saying he is a "scapegoat" for Lebanon's economic collapse.