A fracture in a straight section of track 'occurred prior to the passage' of a high-speed train that derailed, causing last Sunday's rail disaster in which 45 people died, an initial report has found.
A train run by private company Iryo derailed last Sunday and its rear carriages crossed onto the opposite track into the path of an oncoming train run by state-owned Renfe.
The CIAF rail investigation commission reported that not only did the front carriages of the Iryo train, which stayed on the track, have 'notches' in their wheels, but three earlier trains that traveled over the same track did too.
A gap of almost 40cm (15in) in the track is the focus of the investigation into the crash.
Sunday's deadly collision occurred at around 19:45 local time (18:45 GMT), about an hour after the Iryo train left Málaga for Madrid.
The train's last three carriages - carriages six to eight - derailed and collided with the Huelva-bound Renfe train. Carriage six derailed due to a complete lack of continuity in the track, states the preliminary report.
Most victims were in the front carriages of the state-operated train.
Earlier this week, Spanish Transport Minister Óscar Puente confirmed that grooves were found on the Iryo train's wheels, which had previously passed over the track safely.
The CIAF report indicated grooves matching the fractured track were observed across multiple train carriages. The investigation characterized its findings as a 'working hypothesis,' emphasizing that further detailed analysis is required.
The Adamuz train disaster is Spain's worst rail incident in over a decade, echoing the 2013 tragedy in Galicia that left 80 dead.
