Bernard Madoff's bankruptcy trustee and his law firm have asked a federal judge to approve more than $22.1m in fees for five months of work trying to recover money for the victims of the fraudster's $65bn Ponzi scheme.

Irving Picard is the court-appointed trustee liquidating Mr Madoff's former business for Securities Investor Protection Corporation, the non-government agency that helps customers of failed brokerages.

He was appointed in mid-December last year, just days after Mr Madoff was arrested. If the latest fees are approved, the total bill for Mr Picard and his law firm, Baker & Hostetler, since then would amount to more than $37.5m.

"No single document could comprehensively set forth all of the tasks engaged in by the trustee since his appointment," Mr Picard said in a court filing yesterday, as he requested fees for work from May to the end of September.

Mr Picard said the process required "intensive investigation" and involved hundreds of subpoenas. He has filed 14 lawsuits seeking more than $14.8bn from "feeder funds" and others. He is involved in litigation in Europe, Gibraltar and throughout the Caribbean.