The lawyer, David Sheehan, said $75 million in an account in Gibraltar raises the amount of assets located past the $1 billion mark.
Sheehan spoke after a hearing in which government lawyers tried to block court-appointed trustee Irving Picard from gaining power of attorney over Madoff's international operation.
Sheehan argued that power of attorney over Madoff's accounts is an important tool, especially since actions may need to be taken quickly in foreign countries where things can happen to assets without warning.
For instance, Sheehan said, the trustee has been told that French authorities were planning to seize Madoff's chateau in Cap d' Antibe, France. The property was estimated by Madoff to be worth $1 million at the end of 2008, with $900,000 in furnishings and fine art inside it.
Sheehan said he understood that French authorities wanted to seize the property to benefit investors in France who lost money to Madoff.
"Those things happen almost daily," he told U.S. District Judge Louis L. Stanton, saying the trustee needs a strong hand in dealing overseas.
But Assistant U.S. Attorney Barbara Ann Ward said U.S. authorities already have relationships in foreign countries and can act quickly to protect investor assets.
She said any assets in Madoff's international business account should be held in escrow, although prosecutors could agree to allow some movement if action is necessary to protect them.
The judge repeatedly asked Ward if she thought the trustee could not be trusted or was doing something wrong.
"It has nothing to do with mistrusting the trustee or anyone else," she said. "The trustee has not explained why the trustee needs this power."
Ward said U.S. prosecutors were working with law enforcement authorities in other countries, including the Serious Organised Crime Agency in London.
She said there were "criminal implications" involved in Madoff's international securities business. The judge did not immediately decide the issue.
Madoff, 70, was sent to prison nearly two weeks ago after he pleaded guilty to charges that he ripped off thousands of investors for billions of dollars. He was arrested in December after confessing to his sons that his private investment business was a giant fraud.
The government has said he informed investors at the end of November that they had nearly $65 billion in their accounts. Investigators say the figure was most likely based on what accounts originally valued at less than $20 billion would be worth if he had delivered the steady profits he promised.
By Associated Press Writer Larry Neumeister