The UK, France and Germany on Sunday demanded evidence from Saudi Arabia to back its claim that Jamal Khashoggi died in a brawl at its consulate.

In a joint statement, they said Riyadh's explanation - that the dissident journalist was killed when an argument spiralled out of control - needed "to be backed by facts" amid growing scepticism about the Saudi version of events.

Meanwhile a senior official in Riyadh said Khashoggi's body had been smuggled from the consulate wrapped in a rug even as Saudi Arabia’s foreign minister appeared on American TV to claim authorities still did not know exactly how the 59-year-old died or where his body was.

In his strongest comments yet, President Recep Tayyip Erdogan of Turkey said on Sunday that Ankara would release "the naked truth" in the form of a full report on Tuesday.

In the joint statement Jeremy Hunt, the Foreign Secretary, Jean-Yves Le Drian, his French counterpart, and Germany's Heiko Maas condemned the killing.

“Yet there remains an urgent need for clarification of exactly what happened on October 2 - beyond the hypotheses that have been raised so far in the Saudi investigation, which need to be backed by facts to be considered credible,” they said.