A Turkish columnist has appeared in court on World Press Freedom Day, accused of insulting President Recep Tayyip Erdogan.

Murat Belge, an academic who writes for Taraf newspaper, faces four years in prison if found guilty of insulting the Turkish leader in a column suggesting that Erdogan reignited a conflict against Kurdish rebels for electoral gains.

Belge denied insulting Erdogan during the opening hearing on Tuesday, which Nobel laureate Orhan Pamuk attended in a show of solidarity.

Close to 2,000 cases have been opened against people accused of insulting Erdogan. Critics say Erdogan is exploiting a previously-seldom used law to muzzle dissent.

Belge quipped: "I am a member of one of Turkey's most populous clubs — the club of people who have insulted Erdogan."