Turkish writer Orhan Pamuk, who was granted a Nobel Prize in literature in 2006, has condemned the Erdogan government’s methods of investigating the roots of the coup which took place in the country July 15 and was suppressed the next day.

According to the Nobel laureate, the ongoing major crackdown following the attempted coup is unlawful and deprives the citizens of Turkey of basic human rights and freedoms.

In Turkey, you can be thrown in jail if you disagree with the government even slightly, he wrote in the opinion piece published on Sunday in La Repubblica newspaper.

"Freedom of thought no longer exists." Pamuk wrote, adding that there is no future in the country for those who courageously fight for the freedom of speech.

"We are distancing ourselves at high speed from a state of law and heading towards a regime of terror."

The 64-year-old novelist claimed that mass arrests taking place in Turkey are the result of "the most ferocious hatred" and called on Turkish President Recep Tayyip Erdogan to immediately release all intellectuals held in custody so that they can have a fair trial.

Pamuk's comments come just a day after the arrest of brothers Ahmet Altan, the founder of the now closed liberal and opposition daily Taraf, and Mehmet Altan, who has written several books on politics in Turkey.

The brothers are reportedly being investigated over remarks they made in a talk show broadcast on the eve of the attempted coup and accused of being linked to the movement of US-based cleric Fethullah Gulem, who Ankara believes played a key role in the attempted putsch.

Gulen has repeatedly denied the accusations and condemned the coup.

Members of Turkey's armed forces on July 15 tried to stage a military coup. They began with a statement saying they had seized control of Turkey "to reinstall the constitutional order and democracy". Erdogan declared in the early hours of July 16 that he had maintained control of the country.

Over 40,000 academics, teachers and journalists have already been detained in connection with the July 15 events, and over 100,000 individuals dismissed from their jobs.