The interior minister said he would now be questioned by a judge on Sunday. Under Spanish law, a suspect can be detained for a maximum of 72 hours before being heard by a judge.
"There are reasonable grounds to consider that he may have been responsible for what happened, which must be established by a judge and the investigation which has been opened," Mr Fernandez said.
The country's railway agency has said it was the driver's responsibility to brake before going into the high-risk curve where the train tumbled off the rails and smashed into a wall. But it's still not clear whether the brakes failed or were never used.
A blood-soaked Mr Garzon was photographed Wednesday being escorted away from the wreckage, at first by civilians who had hurried to the scene of the accident and then by police, but it is not clear just what his medical status is.
Unconfirmed media reports said that Mr Garzon had injured ribs.
The justice department had said that Mr Garzon would likely testify before a judge on Saturday, but said in a statement it intended now to wait until the 52-year-old is able to appear in court rather than having a judge come to his hospital bedside.
He had been expected to give a preliminary statement to judicial police as early as Thursday, but that process was delayed, reportedly due to health reasons.
In Wednesday's crash, the train's eight carriages packed with 218 passengers blazed far over the speed limit into a curve and violently tipped over. Diesel fuel powering the engine sent flames coursing through some cabins.
The president of Adif, the Spanish rail agency, said that the driver should have started slowing the train 4 kilometers (2.5 miles) before the dangerous bend. He said signs clearly marked this point when the driver must begin to slow.
Although Sunday's court hearing will be closed, it will provide hints about the status of the investigation. The judge will decide whether to jail the driver as an official suspect, release him on bail, or release him without charges. If a judge finds sufficient evidence for a criminal trial, the suspect will be charged and a trial date set.
Edited by Hannah Strange
"There are reasonable grounds to consider that he may have been responsible for what happened, which must be established by a judge and the investigation which has been opened," Mr Fernandez said.
The country's railway agency has said it was the driver's responsibility to brake before going into the high-risk curve where the train tumbled off the rails and smashed into a wall. But it's still not clear whether the brakes failed or were never used.
A blood-soaked Mr Garzon was photographed Wednesday being escorted away from the wreckage, at first by civilians who had hurried to the scene of the accident and then by police, but it is not clear just what his medical status is.
Unconfirmed media reports said that Mr Garzon had injured ribs.
The justice department had said that Mr Garzon would likely testify before a judge on Saturday, but said in a statement it intended now to wait until the 52-year-old is able to appear in court rather than having a judge come to his hospital bedside.
He had been expected to give a preliminary statement to judicial police as early as Thursday, but that process was delayed, reportedly due to health reasons.
In Wednesday's crash, the train's eight carriages packed with 218 passengers blazed far over the speed limit into a curve and violently tipped over. Diesel fuel powering the engine sent flames coursing through some cabins.
The president of Adif, the Spanish rail agency, said that the driver should have started slowing the train 4 kilometers (2.5 miles) before the dangerous bend. He said signs clearly marked this point when the driver must begin to slow.
Although Sunday's court hearing will be closed, it will provide hints about the status of the investigation. The judge will decide whether to jail the driver as an official suspect, release him on bail, or release him without charges. If a judge finds sufficient evidence for a criminal trial, the suspect will be charged and a trial date set.
Edited by Hannah Strange