ISTANBUL (Reuters) - The leader of Turkey’s nationalist party compared Saudi leaders to Osama bin Laden on Tuesday and said the net was closing around Crown Prince Mohammed bin Salman over the murder last month of Saudi journalist Jamal Khashoggi.

The comments by MHP leader Devlet Bahceli, a parliamentary ally of President Tayyip Erdogan, amounted to the fiercest Turkish criticism of the Saudi monarchy since Khashoggi was killed on Oct. 2 by Saudi agents at the kingdom’s Istanbul consulate.

President Tayyip Erdogan has said the killing was ordered at the “highest levels” of the Saudi government but has not directly accused its de facto leader, Prince Mohammed. Saudi Arabia has denied that the prince ordered Khashoggi’s killing.

In a speech to his Nationalist Movement Party on Tuesday, Bahceli said Saudi leaders had resorted to terrorist methods.

“I ask you, what difference remains between Saudi Arabia’s administration and the mentality of Osama bin Laden? What separates this country from al Qaeda?” Bahceli said. “The circle is closing in for the crown prince, the paths of escape and salvation are closing.”

Bahceli’s MHP supported Erdogan in Turkey’s presidential election in June, helping him secure a narrow first-round victory. Its alliance with Erdogan’s AK Party also ensured a parliamentary majority for the AKP.

The CIA believes Crown Prince Mohammed ordered Khashoggi’s killing, sources familiar with the matter said on Friday - an assessment described by U.S. President Donald Trump as possible, but very premature.

A source familiar with the CIA’s assessment said it was based largely on circumstantial evidence relating to the prince’s central role in running the Saudi government.

Saudi Arabia’s foreign minister said on Tuesday his country categorically rejects allegations against the crown prince, saying they had no basis in truth.

Last week, after Riyadh offered numerous contradictory explanations for Khashoggi’s disappearance, the Saudi public prosecutor’s office said he had been killed, after a struggle, by lethal injection and his body dismembered.