International media advocacy group Reporters Without Borders on Wednesday called for an independent international investigation into the fate of Jamal Khashoggi — the Saudi journalist who has been missing since October 2 — saying his disappearance has come amid "a particularly harsh and opaque crackdown on Saudi journalists and bloggers".

The same day, Turkish media published images of an alleged 15-member Saudi “assassination squad” and video of suspicious movements at the Saudi Consulate in Istanbul following Khashoggi’s disappearance, putting new pressure on the kingdom amid growing international concern for the writer.

Saudi Arabia remained silent as the images, though not offering definitive proof about Khashoggi’s fate, played across television networks in Turkey and around the world. Turkish officials fear the team killed Khashoggi, who wrote critically of Saudi Crown Prince Mohammed bin Salman. The kingdom dismisses the allegation as “baseless”.

RSF, in a statement on its website, highlighted that "more than 15 journalists and bloggers have been arrested in a completely opaque manner in Saudi Arabia since September 2017".

"In most cases, their arrests have never been officially confirmed and no official has ever said where they are being held or what they are charged with," said the watchdog.

"This was the case with Salehel Shihi, a journalist whose arrest was only confirmed in February, when his family learned than he had been sentenced to five years in prison. He disappeared in December 2017 but his detention was not made official until his conviction and sentence were announced," said RSF.

"The Saudi journalist and commentator Turad Al Amri has been missing since November 2016. In one of his last tweets, he condemned the clampdown on the Saudi media and, in particular, the blocking of an online newspaper for which he had written a sensitive article."

“The traditionally opaque methods used by Saudi Arabia to silence critical journalists constitute grounds for fearing the worst in the case of Jamal Khashoggi’s disappearance,” said Sophie Anmuth, the head of RSF’s Middle East desk. “We call for an independent international investigation to determine as quickly as possible what has happened to Khashoggi.”

A day earlier, Turkish foreign ministry spokesman Hami Aksoy said in a statement that “Saudi authorities said they were open to cooperation and that a search can be conducted at the consulate building".

The search will take place as part of the official investigation, which was being conducted “in an intense manner”, he said without giving any date.

Saudi Arabia is currently ranked 169th out of 180 countries in RSF’s 2018 World Press Freedom Index.