Governments have uncovered trillions of dollars in offshore funds since they began sharing in bulk bank account details last September, the Organisation for Economic Cooperation said on Friday.

More than 90 governments have shared details about 47 million offshore accounts with other governments since the large-scale exchange of bank details began, the OECD said in a statement.

The information includes balances and transactions on accounts holding a combined 4.9 trillion euros ($5.5 trillion), the Paris-based policy advisory forum said, more than the gross domestic product of Japan.

Also read: A global financial registry to fight tax evasion

Under the OECD's common standard for reporting account details, participating countries started automatically sharing bank account information in September.

The move was the culmination of a two-decade international clampdown on tax evasion that has all but ended bank secrecy in many financial centres.

“The transparency initiatives we have designed and implemented through the G20 have uncovered a deep pool of offshore funds that can now be effectively taxed by authorities worldwide,” OECD head Angel Gurria said in a statement.

Gurria, who is to present the data to finance ministers of the Group of 20 economic powers at a meeting in Japan this weekend, said tax compliance was already improving.

Tax authorities booked more than $95 billion in extra revenue thanks to voluntary disclosures before automatic information sharing went live in September, the OECD said, raising its estimate by $2 billion from November.