Key evidence in the London inquiry into the murder of a Russian spy in 2006 won't be heard this week as planned after a Russian witness pulled out.
Dmitri Kovtun is thought to have been involved in the murder of Alexander Litvinenko in London, and was due to give evidence (starting on Monday) via videolink from Russia.
UK correspondent Olly Barratt says his decision not to give evidence deprives the inquiry of crucial testimony.
IN: "Whether...
OUT: ...and Moscow."
DUR: 60 seconds