Eighty-year-old Edgar Ray Killen, found guilty this week of manslaughter in the deaths of three civil rights workers in Mississippi in 1964, was sentenced Thursday to 60 years in prison.

The former KKK leader was sentenced to 20 years in prison on each manslaughter count, with the sentences to run consecutively. Manslaughter carries a maximum sentence of 20 years.

Killen was convicted Tuesday, 41 years after the deaths of James Chaney, a black from Mississippi, and his white colleagues, Andrew Goodman and Michael Schwerner from New York.

Convicted killer Edgar Ray Killen is rolled away from the Neshoba County courthouse after being sentenced to 60 years in prison,Thursday, June 23. (AP photo /The Neshoba Democrat )

Killen had been tried on murder charges. But the prosecutor's office had indicated that it would be satisfied with the lesser verdict of manslaughter in order to get a conviction in the crime.

Killen's conviction will be appealed on the grounds that the defence objected to jurors being given the option of convicting him on the lesser crime, his legal team said.

The case had cast a pall over the town of Philadelphia, Miss., since the three men's beaten and shot bodies were found during what became known as "Freedom Summer," when civil rights workers tried to register black voters in the segregated state.

The three were in Philadelphia to investigate the burning of a church used to register black voters when they were ambushed by a gang of Ku Klux Klan thugs.

Their bodies were found more than six weeks later.

The case was made famous in the 1988 film, Mississippi Burning.

Killen, a part-time preacher, was the only man ever indicted on state murder charges in the case, but he was not brought to trial on those charges until this year.