The contractors who carried out repairs of the ill-fated suspension bridge at Morbi in Gujarat were not qualified to carry out such jobs, the prosecution told a court here on Tuesday.

The collapse of the bridge on Sunday evening claimed 135 lives.

While the flooring of the bridge was replaced, its cable was not replaced and it could not take the weight of the changed flooring, said the prosecution, citing a forensic report.

The magistrate's court remanded four of the arrested accused -- two managers of OREVA Group and two sub-contractors who had repaired the bridge -- in police custody till Saturday.

Chief Judicial Magistrate M J Khan remanded five other arrested men, including security guards and ticket booking clerks, in judicial custody as police did not seek their custody, said prosecutor H S Panchal.

Police had on Monday booked nine persons under Indian Penal Code section 304 (culpable homicide not amounting to murder).

The four who were remanded in police custody were OREVA managers Dipak Parekh and Dinesh Dave, and repairing contractors Prakash Parmar and Devang Parmar, hired by the OREVA Group.

Citing Forensic Science Laboratory (FSL) report, Panchal told the court that forensic experts believed that the main cable of the bridge snapped because of the weight of the new flooring.

"Though the FSL report was presented in a sealed cover, it was mentioned during the remand plea that cables of the bridge were not replaced during the renovation and only flooring was changed..... weight of the bridge increased due to the four-layered aluminium sheets for the flooring and the cable snapped due to that weight," Panchal told reporters.

The court was also informed that both the repairing contractors were "not qualified" to carry out such a work.

"Despite that, these contractors were given repair work of the bridge in 2007 and then in 2022. So the accused's custody was needed to find out what was the reason for choosing them and at whose instance they were chosen," the prosecutor said.