World powers should reconsider holding the next Group of 20 summit in Saudi Arabia without accountability over the killing of Jamal Khashoggi, a UN expert who probed his death said Tuesday.

An official Saudi Arabian investigation into the murder of journalist Jamal Khashoggi by Saudi agents failed to examine who may have ordered the killing and ignored key suspects, a UN special rapporteur said on Wednesday.

The death of Saudi dissident journalist Jamal Khashoggi warrants further UN investigations, his fiancee Hatice Cengiz said on Tuesday on the sidelines of the UN Human Rights Council in Geneva.

Saudi Arabia has sought to move on from the scandal triggered by journalist Jamal Khashoggi's murder, but a UN expert's report implicating its crown prince has heaped pressure back on the kingdom, analysts say.

Saudi Crown Prince Mohammed bin Salman and other senior Saudi officials should be investigated over the murder of journalist Jamal Khashoggi since there is credible evidence they are liable for his death, a UN rights investigator said on Wednesday.

Turkey has arrested two men suspected of spying for the United Arab Emirates and is probing if they are tied to Saudi journalist Jamal Khashoggi's murder, Anadolu state news agency said on Friday.

Members of the Saudi team that killed journalist Jamal Khashoggi received training in the United States, the Washington Post has reported, revealing other new elements in the death of the newspaper's former contributor.

The European Parliament on Tuesday heard, for the first time, "horrific testimonies" by two of the victims of the unjust blockade imposed on Qatar and three others who have also been victims of violations of human rights by Saudi Arabia, the UAE and Bahrain.

Turkish President Tayyip Erdogan urged the United States to put its weight behind the investigation into the killing of Saudi journalist Jamal Khashoggi and not to set the matter aside because of its ties with Riyadh.

President Donald Trump appeared prepared to ignore the US Congress's Friday deadline to determine who ordered the assassination of Jamal Khashoggi amid new revelations that Saudi Arabia's crown prince spoke of threatening the journalist with a "bullet."

A United Nations investigation into the killing of Saudi journalist Jamal Khashoggi has to be launched, Turkish Foreign Minister Mevlut Cavusoglu said on Friday.

The Turkish fiancee of murdered Saudi journalist Jamal Khashoggi said Friday she hoped pressure from the US Congress would encourage the Trump adminstration to take a tougher stance on the killing.