Saudi journalist Jamal Khashoggi was strangled as soon as he entered the country’s Turkish consulate before his body was dismembered, Istanbul’s chief prosecutor has said in what was seen as an attempt by Turkey to pressure Riyadh over the investigation.

Irfan Fidan said the killing of the dissident writer was planned and that he had asked Saudi prosecutor Saud al-Mojeb to reveal the location of the body.

The statement came after Mr Fidan and Mr Mojeb carried out inspections at the Saudi consulate in Istanbul, where Mr Khashoggi was killed earlier this month, and held meetings with Turkey’s public prosecutor and Turkish intelligence officials.

“Despite our well-intentioned efforts to reveal the truth, no concrete results have come out of those meetings,” said Mr Fidan in the statement.

Mr Fidan’s statement did not confirm rumours that Ankara possesses audio or visual recordings capturing the Washington Post columnist’s final moments. Unnamed Turkish officials had previously told media that Mr Khashoggi had been killed and dismembered, but Mr Fidan’s statement marked the first official confirmation.

Turks have grown quickly frustrated with their Saudi counterparts, whom they accuse of attempting to derail and obfuscate the murder. Turks keep asking who ordered the 18-man operation to murder Mr Khashoggi and what happened to the victim’s body. They have received no satisfactory answers.

“They were more interested in finding out what we had on the killers than share information with us,” said a source close to the Turkish government. “Instead of answering very simple questions, they invited the Turkish investigators to Saudi Arabia. It looks like an attempt to run down the clock until nobody cares any more.”

Saudi Arabia has continually changed its story regarding the affair. Days after Mr Khashoggi walked into the consulate and was murdered, Crown Prince Mohammed bin Salman, believed by many world leaders to have ordered the hit, told Bloomberg to ask the Turks what happened to Mr Khashoggi.

After insisting for weeks that Mr Khashoggi had walked out of the consulate, the Saudis claimed he died in a scuffle with their own agents seeking to entice him to return home, with the panicked operatives disposing of his body hastily disposed of by “a local collaborator.” As more evidence was leaked, Saudi Arabia admitted the killing was a “premeditated” plot but refused to say who ordered it.

In his statement the Turkish prosecutor accused his Saudi counterpart of again revising Riyadh’s account by falsely claiming that “no statement had been made by the authorities of the kingdom of Saudi Arabia regarding the existence of a ‘local collaborator’”.

Riyadh and Ankara have clashed even over basic jurisdictional matters. Turkey is seeking the extradition of 18 Saudi suspects detained in Saudi Arabia over Mr Khashoggi’s killing, insisting that as the crime was committed on Turkish soil they have a duty to prosecute it. Saudi officials have said the kingdom will try the 18 suspects and bring them to justice because they are their own citizens who allegedly killed another citizen in a Saudi diplomatic facility.

Jamal Khashoggi death: key figures Show all 7 1 /7 Jamal Khashoggi death: key figures Jamal Khashoggi death: key figures Jamal Khashoggi Washington Post journalist who was critical of the Saudi regime and the young Crown Prince Mohammed bin Salman, he was murdered on 2 October in the Saudi Arabian consulate in Istanbul AFP Jamal Khashoggi death: key figures Saudi Crown Prince Mohammed bin Salman Heir to the Saudi throne, Mohammed bin Salman has been implicated in the murder, with US officials claiming that he must have known of the plot AFP/Getty Jamal Khashoggi death: key figures 15 man hit squad Turkish police suspect these 15 men of being involved in the murder of Jamal Khashoggi, issued 10 October, 8 days after the journalist disappeared EPA Jamal Khashoggi death: key figures Saud al-Qahtani Aide to Crown Prince Mohammed bin Salman, Saud al-Qahtani is claimed to have ordered Khashoggi's murder Saud Al-Qahtani/Twitter Jamal Khashoggi death: key figures Maher Abdulaziz Mutreb A former diplomat who often travelled with the Crown Prince, Mutreb was initially claimed to be the leader of the hit squad and is pictured here entering the Saudi consulate on the day of the murder AP Jamal Khashoggi death: key figures Mustafa al-Madani First implicated in the 15 CCTV photos released by the Turkish police, al-Madani was later found to have been used as a body double for Khashoggi, leaving the Saudi consulate dressed in his clothes on the day the journalist was killed CNN Jamal Khashoggi death: key figures Salah bin Jamal Khashoggi (L) Son of the murdered journalist met with Crown Prince Mohammed bin Salman on 23 October EPA

The public airing of differences between Saudi Arabia and Turkey came as a group of Republican senators asked Donald Trump to suspend civilian nuclear talks with Saudi Arabia over the murder and its actions in Yemen and Lebanon.

Justice for Jamal Khashoggi protest outside the Embassy of Saudi Arabia

The five US lawmakers, led by senator Marco Rubio, said they would use the Atomic Energy Act to block any US-Saudi nuclear agreements if Mr Trump did not cut off talks.

“The ongoing revelations about the murder of Saudi journalist Jamal Khashoggi, as well as certain Saudi actions related to Yemen and Lebanon, have raised further serious concerns about the transparency, accountability, and judgment of current decision makers in Saudi Arabia,” the senators wrote.