Many of Madoff's victims have already demanded that he should never be released - but his lawyers are hoping for a sentence of 12 years

Bernard Madoff's was handed 150 years in prison for his $65bn (£39.5bn) fraud.

The hearing in New York started at 10am local time (3pm BST) and up to 11 victims told the court how they have been hurt by the sudden, unexpected loss of their savings.

Many of these victims have already demanded that Madoff should never be released. Assistant US attorney, Marc Litt, has backed that view, arguing that the "scope, duration and nature" of Madoff's activities mean the disgraced 71-year-old should receive the maximum sentence of 150 years.

Madoff pleaded guilty in March to a range of charges, including securities fraud, money laundering and perjury. Over 13,000 people lost money through the collapse of Madoff Securities – famous victims include actor Zsa Zsa Gabor and film director Steven Spielberg.

Before sentencing, the court heard victim impact statements. Over 100 people wrote to Chin to explain how they have suffered from the fraud. Many lost all the money they put aside for retirement, or to pay college fees. Although some were already wealthy, meeting Madoff on the New York social circuit, others were of more modest means and sometimes were not even aware their money had been invested with Madoff.

The tone of today's hearing was set by victims such as Jesse Cohen, who called Madoff "a thief and a monster". Another victim, Ronnie Sue Ambrosino, wrote that "the birds that had been chirping stopped singing. The sun stopped shining" after she and her husband learned they had lost their life savings.

Madoff claimed for decades that he delivered market-beating returns through canny investments in shares and bonds. But in reality, his empire was a Ponzi scheme in which money was moved around the world to give the impression of successful trading, and money from new clients was used to pay off old ones.

Detectives are now investigating Madoff's wife, Ruth, and the couple's children Andrew and Mark. Both sons worked for Madoff, but claimed they had no knowledge of the fraud. But once today's court hearing is completed, prosecutors are expected to intensify their efforts.

"In a case as complex as this, we are taking one step at a time," a source close to the US attorney's office told the Observer. "When Madoff is sentenced, that will be one major step completed which will free up resources for the investigation to shift to others."