According to Turkish TV channel NTV, Dink - a Turkish citizen of Armenian descent - was shot three times in the neck around midday. He was the columnist and managing editor of Agos, a bilingual Turkish-Armenian weekly newspaper. He spoke openly about the Armenian massacres of 1915-17 committed by Turks under the Ottoman Empire.
On Saturday, Istanbul Police arrested a 17-year-old boy identified as Ogun Samast, a student at Ankara University, who has since confessed to Dink's murder, Turkish news agency Anatolia and other judicial sources say. A gun, believed to have been used in the crime, was also found with the boy.
Prior to his tragic death, Dink received many death threats, which he reported to the police but said nothing was apparently done.
Both the Committee to Protect Journalists (CPJ) and Reporters Sans Frontieres - Reporters without Borders (RSF) have condemned the murder.
"Through his journalism, Dink sought to shed light on Turkey's troubled past and create a better future for Turks and Armenians. This earned him many enemies, but he vowed to continue writing despite receiving many threats," CPJ executive director Joel Simon said.
"An assassin has now silenced one of Turkey's most courageous voices. We are profoundly shocked and saddened by this crime and send our deepest condolences to Hrant's family, colleagues and friends."
RSF, through a statement posted on the UK-based website Media Helping Media, said: "This murder will distress and disturb all those who defend the freedom of thought and expression in Turkey and elsewhere.
"This will be a key test for a country that hopes to join the European Union. No one would understand if Turkey failed to do everything possible to shed a light on this tragedy."
The Turkish government put Dink on trial several times over his hard-hitting articles which it said were based on 'false claims' of genocide. And in 2005, he was convicted of 'insulting' Turkish identity and given a six-month suspended sentence. Turkish Nationalists, angered by this lenient sentence, frequently threatened to kill him.
His alleged killer, turned in by his father after identifying him from the widely-publicised CCTV pictures, has allegedly confessed to having killed Dink because he insulted the Turkish people. Police said they have also arrested six other people in connection with the journalist's murder.
The funeral will take place on Tuesday in Istanbul.
