The conviction of a renowned Turkish pianist for 'denigrating Islam' on Twitter sends a "chilling" message to social media users in the country, Amnesty International said today.

Fazil Say, who has played in some of the world's leading orchestras, was today given a 10-month suspended sentence for posting tweets mocking religious individuals and Islamic conceptions of heaven in April 2012.

"The conviction of Fazil Say is a flagrant violation of his freedom of expression, made possible by one of Turkey's most draconian laws," said Andrew Gardner, Amnesty International’s expert on Turkey.

"This case sends a chilling warning to anyone using Twitter or other social media in Turkey. Namely, that if you express an opinion the authorities don't like, you could be next."

Charges against Say cited nine tweets on his account, including a re-tweet saying: "I am not sure if you have noticed, but where there's a louse, a non-entity, a lowlife, a thief or a fool, they are all Islamists. Is this a paradox?"

A package of reforms passed on 12 April by Turkey's Parliament – called the 'fourth judicial package' – failed to overhaul the county’s outdated and restrictive laws curtailing freedom of expression.

Say, who has played with the New York Philharmonic, the Berlin Symphony Orchestra and others, said he was "saddened" by the verdict.

"I am very disappointed for freedom of expression. The fact that I have been convicted despite not having committed a crime is more worrying for the right to freedom of expression and belief in Turkey than it is for me personally," the pianist reportedly told Turkish media today.

By the terms of Say's sentence, he faces jail is he is found guilty of the same offence within the next five years.

"This conviction exposes the unjust Turkish laws that leave people vulnerable to a range of abuses - including jail - just for expressing an opinion," said Gardner.

“In failing to make the required reforms in the fourth judicial package, the government missed a great opportunity to bring Turkey’s laws in line with international human rights standards.

“The government must look again at its reform agenda and immediately abolish offences such as the one used to prosecute Fazil Say.”