Making the biggest arrests yet in the case, the Mumbai Police on Thursday arrested two senior civic engineers as part of their probe into the BMC’s Rs 11-crore roads scam, and termed the head of the civic body’s vigilance department the main accused.

Ashok Pawar, who was chief engineer (roads) when the contracts were awarded to tainted contractors for the repair of 34 roads in the city, and Uday Murudkar, chief engineer (vigilance), were remanded to police custody until July 11 by Additional Chief Metropolitan Magistrate R K Deshpande on Thursday afternoon.

Pawar and Murudkar, both suspended from the BMC, are the 23rd and 24th arrests made by the police, in the case of misappropriation of funds and over-billing.

Pawar, who headed the roads department until he was shunted out in 2015, has been dubbed negligent by the police in overseeing the repairs project, which was his direct responsibility. “He was negligent in checking the condition of the roads while work was being carried out by the contractors,” argued Assistant Public Prosecutor Rajendra Suryavanshi.

The prosecutor also told the court, “Accused 24 (Murudkar) is the main accused. If had been vigilant while doing his job, the offence would not have happened. There was a vast difference in the requirements for works in documents prepared by him and those prepared by the BMC’s inquiry committee,” Suryavanshi said.

The police have alleged that under the direct supervision of Pawar and Murudkar, contractors, engineers, third party quality auditors and the BMC’s engineers conspired together to use smaller quantity of material to repair roads and did not adhere to the designs in the documents, cheating the civic body of Rs 14.45 crore.

The two engineers allegedly also did not disclose to the BMC’s inquiry committee the details of the trucks that were used to ferry construction debris to the dumping ground. The accused allegedly created fake bills in this regard.

The police also want to probe how the vigilance department turned a blind eye to the irregularities in road works taking place under its supervision.