Jack Abramoff, a disgraced former US lobbyist at the heart of a Washington corruption scandal, has been sentenced to four years in prison.

The judge presiding over the case handed down the sentence on Thursday, saying Abramoff had shattered public confidence in government.

Abramoff fought back tears as the judge delivered the sentence - a longer prison term than prosecutors had sought.

"I come before you as a broken man. I'm not the same man who happily and arrogantly engaged in a lifestyle of political and business corruption," Abramoff said.

"My name is the butt of a joke, the source of a laugh and the title of a scandal."

'Broken man'

The once-powerful lobbyist was accused of corrupting politicians with golf junkets, expensive meals and luxury seats at sporting events.

He pleaded guilty in January 2006 to conspiracy, mail fraud and tax evasion.

The corruption scandals involving Abramoff shook Washington and contributed to the Republicans' loss of both legislative houses in 2006, after Democrats used the scandals to suggest there was a climate of corruption in the US capital.

Abramoff has already spent two years in prison in Florida on unrelated fraud charges in the purchase of a Florida casino cruise line.

He will have spent about six years in prison by the time he is released - far longer than he and his attorneys expected for a man who became the key FBI witness in his own corruption case.

With Abramoff's help, the Justice Department won corruption convictions against Boy Ney, a former member of the House of Representatives, J Steven Griles, a former deputy interior secretary and several top congressional aides.

Ellen Segal Huvelle, the district judge presiding, could have sent Abramoff to prison for 11 years but showed leniency because of his assistance with the FBI.

But she rejected proposals to reduce the sentence even further by giving Abramoff credit for the time he has already spent in prison on the fraudulent casino deal.