Former Mumbai police commissioner Param Bir Singh, declared a proclaimed offender by a Mumbai court, arrived in Mumbai on Thursday to join the investigation as directed by the court, an official said.

Singh flew in from Chandigarh, the official said. He has come to join the investigation with the orders of the court and will co-operate the investigation, he added.

"I will join the investigation as directed by the court," Singh told media on arrival.

After leaving the airport, Singh appeared before the Mumbai police crime branch unit-11, where his statement in connection with an extortion case registered at Goregaon police station here will be recorded, the official said.

The IPS officer, who is facing several extortion cases in Maharashtra, had told news channels on Wednesday that he was in Chandigarh.

Singh has not reported to work since May this year, after his transfer from the post of Mumbai police commissioner and his subsequent allegations of corruption against then Maharashtra home minister Anil Deshmukh.

The Supreme Court has granted Singh protection from arrest.

He was transferred after Mumbai police officer Sachin Waze was arrested in the case of an SUV with explosives found near industrialist Mukesh Ambani's house, 'Antilia' and the subsequent suspicious death of businessman Mansukh Hiran.