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 revealed that not only did Iryo train's front carriages, which remained on the track, show signs of damage, but three earlier trains that passed over the track did as well.

A 40cm gap in the track has become the focus of the investigation into the crash. The deadly collision occurred at about 19:45 local time, about an hour after the Iryo train departed Málaga for Madrid, with most casualties occurring in the front carriages of the state-operated train.

Spanish Transport Minister Óscar Puente confirmed grooves were found on the Iryo train's wheels, suggesting the track was already compromised before the incident. The CIAF report emphasizes the need for thorough verification of the findings as they piece together the tragic details surrounding this disaster, which is the worst rail crash in over a decade for Spain.