Hungary plans to impose a 35-percent levy on up to two trillion forints ($9 billion) held in foreign accounts, state news agency MTI reported on Wednesday.
Janos Lazar, Prime Minister Viktor Orban's chief of staff, said a government working group has been set up to trace the funds, which have been estimated at between one and two trillion forints, the agency reported.
The group plans to meet first with Swiss authorities to discuss the transfer of bank information related to Hungarian deposits, Lazar said.
He also mentioned Austria and Cyprus as locations favoured by anonymous Hungarian account holders.
"It's particularly important that bilateral discussions with Cyprus begin so that offshore funds can be brought home and into the tax system as soon as possible," Lazar said.