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 on to the opposite track into the path of an oncoming train run by state-owned Renfe.
The CIAF rail investigation commission stated that not only did the Iryo train's front carriages, which remained on the track, have notches in their wheels, but three earlier trains that traversed the same track did too.
A gap of almost 40cm (15in) in the track has become 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, the preliminary report notes.
Most of those killed and injured were in the front carriages of the state-operated train.
Earlier this week, Spanish Transport Minister Óscar Puente confirmed reports that grooves were found on the Iryo train's wheels, which had previously passed over the track without issue.
These notches in the wheels and the deformation observed in the track are consistent with the fracturing of the track, according to the CIAF preliminary report.
The investigation is still ongoing, with officials emphasizing that it is too early to arrive at definite conclusions regarding the cause of the crash.
The Adamuz disaster is now recorded as the country's most severe rail crash in over a decade, recalling the tragic 2013 derailment in Galicia that resulted in 80 deaths.
