Austria is considering widening an asset freeze list to include a top official at the Libyan Investment Authority because of possible links to Muammar Gaddafi's inner circle, the Foreign Ministry said on Thursday.

The ministry said it had asked Austria's National Bank to consider the measures against Mustafa Zarti, the investment body's deputy chief, following the imposition of international sanctions on Gaddafi's family and associates. Zarti has an Austrian passport, it said.

"There are indications that he is part of the team around Gaddafi and that he might use possible assets in favour of people which are on the list for the asset freeze," Foreign Ministry spokesman Alexander Schallenberg said.

Austria has already taken steps to freeze assets linked to the Libyan leadership. Zarti was not included on an Austrian National Bank list published following sanctions adopted earlier this week by the European Union.

It was not clear whether Zarti or any of the others affected had assets in the country, Schallenberg said, but said Austria was taking precautionary steps in case any of those on the list tried to withdraw money.

The National Bank chief said this week Libyan clients had about 1.2 billion euros (US$1.7 billion) in the country's banks and it was trying to find out how much of this might be connected to people under sanctions.

Zarti, an Austrian citizen since 2006, was close to Gaddafi's son Saif al-Islam who studied in Vienna.

Saif, a friend of the late far-right politician Joerg Haider, lived in a luxury villa on the outskirts of Vienna while in the country and kept his two pet white tigers in the city's zoo.

It was not clear where Zarti was now, Schallenberg said. Austrian media have said he entered the country last month.