Maharashtra Home Minister Anil Deshmukh on Thursday said the sudden transfer of former Mumbai Police Commissioner Param Bir Singh was due to some “serious and unforgivable mistakes” made by his colleagues, PTI reported.

“This is not an administrative transfer,” the minister said. “Some things have come to light through the probes conducted by the NIA [National Investigation Agency] and the ATS [Anti-Terror Squad].”

Singh, who was under fire over the handling of the bomb scare outside industrialist Mukesh Ambani’s house in south Mumbai, was on Wednesday transferred to the low-key Home Guard by the state government. Acting Director-General of Police of state Hemant Nagrale replaced him.

Deshmukh said Singh was shifted to ensure that the investigation in the Ambani case was conducted properly and without hindrance. “Some of the colleagues of the Mumbai police chief committed some serious mistakes,” he added. “Those are unforgivable mistakes. Hence, he was transferred. Further action will be taken based on the probe report.”

Singh had been appointed as the police commissioner of Mumbai in February last year. Before that, he served as the police chief of Thane and deputy commissioner of police in several zones in Mumbai.

Singh’s transfer came two days after the Mumbai Police suspended Crime Branch officer Sachin Vaze. A day before that, he was sent to the National Investigation Agency’s custody for his alleged role in placing the explosives-laden vehicle at Carmichael road, which is close to Ambani’s residence.

On Tuesday, the NIA had seized a black Mercedes, which was allegedly driven by Vaze. The agency recovered the license place of the SUV found outside Ambani’s residence and cash from the car.

The SUV laden with explosives was found outside near Ambani’s residence on February 25. It also had a note threatening the industrialist and his wife Nita Ambani. The car belonged to auto parts dealer Mansukh Hiren, who had filed a stolen report with the police on February 17. Hiren was found dead in a creek near Mumbai on March 5.

Hiren’s wife has alleged that Vaze, the first investigating officer in the bomb scare case, had used the car for four months and returned it on February 5. She has also accused Vaze of having a role in her husband’s death.