TURKEY’S government has reportedly told US officials it has audio and video proof that missing Saudi Arabian writer Jamal Khashoggi was killed and dismembered in the Saudi consulate in Istanbul.

The Washington Post, for which Khashoggi is a columnist, cited anonymous officials as saying the recordings show a Saudi security team detained the writer when he went to the consulate on October 2 to pick up a document for his upcoming wedding.

A delegation from Saudi Arabia has arrived in Turkey as part of an investigation into the writer’s disappearance, Turkey’s state-run news agency Anadolu said.

Saudi Arabia has called the allegation it abducted or harmed Khashoggi “baseless”. However, it has offered no evidence to support its claim he left the consulate and vanished despite his fiancée waiting outside.

Anadolu Agency said the delegation would hold talks with Turkish officials over the weekend. It did not provide further details.

On Thursday, Turkish presidential spokesman Ibrahim Kalin said Turkey and Saudi Arabia would form a “joint working group” to look into Khashoggi’s disappearance.

The 59-year-old journalist, who was considered close to the Saudi royal family, had become a critic of the current Saudi government.