King Salman and Recep Tayyip Erdogan
King Salman and Recep Tayyip ErdoganReuters

One of the fifteen men accused by Turkey of participating in the murder of Washington Post columnist Jamal Khashaggi has died in what Turkish media are calling a "suspicious" car crash.

Mashal Saad al-Bostani, 31, a lieutenant in the Saudi Royal Air Forces, was accused of being part of the 15-member hit squad that allegedly murdered Khashaggi at the Saudi consulate in Istanbul on October 2.

Al-Bostani was killed in a car crash in Riyadh, the capital of Saudi Arabia.

The Turkish Daily Hurryiet news site speculated that Saudi Crown Prince Mohammad bin Salman was looking to destroy the evidence to cover up the murder of Khashaggi, and that Saudi consul Mohammad al-Otaibi could be the next person to be "executed."

Al-Otaibi's voice is believed to have been heard on a recording of the murder which is in the possession of the Turkish government. He is reported to have told the hit squad to "do it somewhere else outside or I will be in trouble" before being told to keep his mouth shut if he wanted to stay alive.

He returned to Saudi Arabia on Tuesday, one day before Turkish police searched his residence in Istanbul.