A train driver suspected of causing Spain's deadliest train disaster for 70 years has refused to answer police questions, Spanish officials have confirmed.
Francisco Jose Garzon Amo, 52, who is under armed guard in hospital, is to be questioned over suspected reckless driving following the devastating crash which left 78 people dead and almost 170 injured.
Investigators are looking into possible failings by the driver after the Madrid to Ferrol service derailed on Wednesday night as it approached the city of Santiago de Compostela.
Authorities have located the train's so-called "black box" which is expected to shed further light on the disaster's cause.
A Spanish police spokesman confirmed the driver had refused to answer questions and he is now expected to questioned by a judge.
Jaime Iglesias, police chief of Spain's northwest Galicia region, said Amo would be questioned "as a suspect for a crime linked to the cause of the accident" and described the alleged offence as "recklessness".
Police said the number of dead, thought to be 80 on Thursday, has been reduced to 78 as forensic science units continue to identify remains.
A spokesman for Spain's National Police said that Amo was arrested in hospital at 8pm on Thursday on suspicion of causing the accident.
Some 72 of those killed in the catastrophe have now been formally identified, while DNA results for the remaining six are expected in the coming days.
One Briton has been confirmed by the Foreign Office to be among the 168 injured passengers, while 32 people are still believed to be in a critical condition.