Nine school officials in Atlanta, Georgia, have been sentenced to prison following convictions for participating in an exam cheating scandal.

Judge Jerry Baxter called the case "the sickest thing that's ever happened in this town".

Three of those convicted received 20-year sentences, far harsher than the penalties asked for by the state.

Evidence of cheating was uncovered at 44 schools with nearly 180 officials involved.

The state-led investigation shocked the city when it discovered that officials at the city-run schools had encouraged teachers to change students' answers in order to demonstrate educational progress.

Thos convicted of 20-year sentences will serve seven years behind bars and 13 years on probation.

Several more received five-year sentences, but will spend only one or two years in prison.

Two others received weekend jail time and home confinement.

Some were also ordered to return the bonuses that they had been given based on the improved test results.

Prosecutors had argued that the plot was a "cleverly disguised conspiracy" to manipulate test scores.

There were several outbursts from the defendants and their lawyers during sentencing.

"You sit down or I'm gonna put you in jail," said Judge Baxter to one of the dozen lawyers in court.

"You keep yelling at me, Judge," the lawyer responded.

Appeals are expected in the coming months.