The first senior Czech communist official has been jailed in Prague for his role in the 1968 Soviet invasion.
Hoffmann ordered broadcasts to stop
Karel Hoffmann, 79, was sentenced for four years for abuse of power. His lawyers said he had been victim of a show trial.
He is the first senior official to be convicted over the invasion, and no other convictions are immediately foreseen.
Hoffmann, then head of state communications, ordered a halt to Czechoslovakian radio and television broadcasts on the eve of the invasion.
The move prevented broadcasters informing the public that the Communist Party leadership in Prague had denounced the military action.
The channels had already been running reports about the brutality of Warsaw Pact troops.
Hoffmann said he would appeal against the verdict, although he welcomed the fact that he had not been found guilty of the more serious charge of treason.
"(The verdict) does not reflect reality but I understand it because political and media pressures are so
strong that the conditions were probably not favourable enough for us to seek a verdict of not guilty," Hoffmann said.
His lawyer said the defence was confident of having the verdict overturned in the Czech supreme court.
"This is an unfortunate political trial. The current ruling elite is belatedly trying to manifest its
anti-communist stance 13 years after taking power," Kolja Kubicek said.
Two other former top communists, former party leader Milos Jakes and ex-prime minister Jozef Lenart were also cleared of treason over the invasion.
The Soviet invasion was launched to end a Czechoslovakian experiment with liberal communism, known as the Prague Spring.
The then Communist Party leader Alexander Dubcek decided to introduce free speech and freedom of assembly, in an attempt to show communism with a human face.
But the Soviet-led invasion on the night of 20 August brutally ended the experiment, killing more than 100 people and arresting Mr Dubcek.
Only two other senior officials have been sentenced over their communist past, but neither was tried over the crushing of the Prague Spring.