ISTANBUL (Reuters) - An adviser to Turkey’s leader said on Wednesday Saudi Arabia’s crown prince had “blood on his hands” over Jamal Khashoggi’s killing, the bluntest comments yet from someone linked to Tayyip Erdogan about Riyadh’s de facto ruler in connection with the death.

Saudi authorities did not immediately respond to a Reuters request for comment about the remarks.

Riyadh has blamed a “rogue operation” for the death of the prominent Saudi journalist, and said Crown Prince Mohammed bin Salman had no knowledge of the killing.

Khashoggi, a Washington Post columnist, disappeared on Oct. 2 when he visited the consulate to obtain documents for his upcoming marriage. After weeks of denying any knowledge of his whereabouts, Saudi Arabia said Khashoggi was killed in a fistfight in the consulate.

The kingdom’s shifting explanations have met incredulity internationally and stirred deepening criticism from Turkey and the West. U.S. President Donald Trump said on Tuesday Saudi authorities staged the “worst cover-up ever”.

“It is a disgrace that reaches all the way to Crown Prince (Mohammed bin) Salman. At least five members of the execution team are (Mohammed bin) Salman’s right hands and are people that wouldn’t act without his knowledge,” Ilnur Cevik, an adviser to President Erdogan, wrote in a column in the Yeni Birlik newspaper.

“Even if U.S. President Trump saves (Mohammed bin) Salman, in the eyes of the world he is a questionable person with Khashoggi’s blood on his hands,” Cevik wrote.

Cevik is one of many Erdogan advisers and not a prominent one. It was not immediately clear whether the views of the column reflected those of Erdogan, who in speeches on Tuesday and Wednesday highlighted the need for all of those responsible - “from those who ordered it to those who carried it out” - to face justice.

Riyadh has detained 18 people and dismissed five senior government officials as part of an investigation into Khashoggi’s death. One of those fired includes Saud al-Qahtani, a top aide to the crown prince.