Mr Meirelles has denied any financial wrongdoing

The finance ministry said it wanted to strengthen his position because of the bank's strategic importance.

But opposition politicians say it was done to give him added legal protection against possible prosecution.

Mr Meirelles has denied any wrongdoing after being accused of failing to declare assets in his tax returns.

No charges have been pressed, but Mr Meirelles has been summoned to appear before the Senate to explain his position.

Under Brazilian law, criminal charges can be brought against members of the cabinet only in the Supreme Court, although they can also be forced to testify before Congress.

Money-changers

The appointment drew strong criticism from one of the main opposition parties in Congress, the Liberal Front Party (PFL).

PFL leader Jose Agripino called the move "an enormous demonstration of political ineptitude".

A news magazine, Veja, has alleged that Mr Meirelles moved $50,000 from a US account to one held by a firm of Brazilian money-changers.

The report followed separate press allegations that Mr Meirelles had filed contradictory tax returns.

All the claims refer to the period before Mr Meirelles, a former top executive at Fleet Boston Financial Corporation, took up his current post.

Mr Meirelles has said he made proper tax declarations before and after moving back to Brazil from the US in 2002.

He has also denied all knowledge of the firm of money-changers.

Brazilian President Luiz Inacio Lula da Silva has been accused of trying to curb press freedom after describing the media allegations against Mr Meirelles as a "witch-hunt".

His government has put forward legislation to create a national journalism council and code of conduct - a move that has been criticised by the president of Lula's own Workers' Party, Jose Genoino, as an effort to influence the press.