US President Donald Trump said on Tuesday Saudi authorities staged the “worst cover-up ever” in the killing of prominent journalist Jamal Khashoggi as Sky News reported that body parts belonging to murdered dissident have been found.

Sky News quoted the sources as saying that the Saudi journalist had been “cut up” and his face “disfigured”.

One source also suggested the writer’s remains were discovered in the garden of the Saudi consul general’s Istanbul home – located around 500 metres away from the consulate.

British Prime Minister Theresa May’s spokesman described the discovery of Khashoggi’s body parts as “deeply disturbing”.

“I am aware of the reports, they are deeply disturbing … the location of Mr Khashoggi’s body is just one of the questions we need answers to and as such we await the full results of the Turkish investigation,” he said.

Speaking hours after Turkey’s President Tayyip Erdogan dismissed Saudi efforts to blame Khashoggi’s death on rogue operatives, President Trump said Saudi authorities staged the “worst cover-up ever” in the murder of the Saudi journalist.

 Erdogan urged Riyadh to search “from top to bottom” to uncover those behind Khashoggi’s death in the Saudi consulate in Istanbul on Oct. 2, an incident that has sparked global outrage and strained relations between Riyadh and Washington.

For Saudi Arabia’s allies, the question will be whether they believe that Crown Prince Mohammed bin Salman, who has painted himself as a reformer, has any culpability.

Trump said the killing and subsequent cover-up by Saudi Arabia were “a total fiasco.”

 “There should have never been an execution or a cover-up, because it should have never happened,” Trump told reporters. He said he had spoken on Monday with the crown prince who denied having anything to do with Khashoggi’s killing.

Earlier, Trump said the Khashoggi matter was handled badly by Saudi officials.

“Bad deal, should have never been thought of. Somebody really messed up. And they had the worst cover-up ever,” Trump told reporters at the White House.

Khashoggi, a critic of the crown prince, was a US resident and Washington Post columnist.

Trump’s comments in recent days have ranged from threatening Saudi Arabia with “very severe” consequences and mentioning possible economic sanctions, to more conciliatory remarks highlighting the country’s role as a U.S. ally against Iran and Islamist militants, as well as a major purchaser of U.S. arms.