US authorities have seized a house and two boats belonging to Bernie Madoff, the disgraced US financier, in the latest bid to recoup assets for duped investors.

Federal marshals arrived at the Palm Beach, Florida mansion late on Wednesday in order to secure the property, conduct an inventory of its contents and change the locks, a spokesman said.

They also seized a yacht reported to be worth about $2m and a smaller boat in two marinas on Florida's east coast.

Madoff is awaiting sentencing after pleading guilty in New York last month to running a massive $65bn "pyramid scheme" that defrauded thousands of investors. He faces life in prison.

'Feeder fund' charged

The news comes as the authorities in the US state of Massachusetts filed civil fraud charges against a "feeder fund" known as Fairfield Greenwich Group which was linked to Madoff.

William Galvin, the Massachusetts secretary of state, said in the civil complaint that there was a "profound disparity" between the due diligence checks Fairfield told clients it was making on Madoff and those actually made.

Galvin did not say how many Massachusetts residents were affected or how much money had been lost.

He is asking that Fairfield Greenwich return the fees that investors paid and the money they invested, as well as pay an administrative fine.

However Fairfield Greenwich said in a statement the allegations were false and misleading and that it planned to "vigorously" contest them.

On Tuesday a judge in the US state of Connecticut froze the assets of Madoff's sons and five top hedge fund industry officials, including three Fairfield Greenwich executives.