European Union prosecutors have begun investigating the possible misuse of EU funds meant for upgrading the Spanish railway line where a train crash killed 69 people last week.

Prosecutors backed by a special unit of Spain’s Guardia Civil security force said they were conducting the inquiry at the offices of Adif rail infrastructure authority and rail safety agency AESF.

The 28 October accident on the Madrid-Seville high-speed line was one of the worst railway disasters in Europe this century.

It is the second EU fraud inquiry opened into Spain’s railways this year, after 46 people were killed on the same line at Adamuz in January.

Last week, a train operated by state-owned operator Renfe ploughed into the back of a stationary train belonging to private Spanish company Iryo outside the village of Urda, around 130km (80 miles) south of Madrid.

The LZB communication system that monitors the position of trains had gone down, and the Renfe train had been given the all clear to start running at normal speed, even though the Iryo train ahead of it had been unable to restart.

The two accidents nine months apart on the same line have claimed 115 lives and dozens more injuries.