Irving Picard, the trustee in charge of recovering assets from Bernard Madoffâ??s fraudulent investment operations, said on Wednesday $21.2bn had been lost through Madoff's Ponzi scheme, an amount far higher than was thought as recently as June.

Mr. Picard, who initially estimated that $13bn was missing, said after examining accounts dating back to 1983 the losses were deeper and could continue to grow as more claims were made.

The Securities Investor Protection Corporation has so far repaid $534m to 1,368 Madoff victims, an amount that already exceeds the total payouts in all 321 previous brokerage liquidations made by the agency since its inception in 1970.

In spite of that progress, the money returned to investors represents only about one eighth of the $4.4bn in claims that the trustee has agreed to consider. To date 2,861 Madoff customers have made claims.