Mohammed Ajmal Amir Iman was held by Indian security forces after he opened fire on crowds at the city's main railway station on November 26.

'We have remand up to 6th of January,' said the officer in charge of the investigation, Mumbai crime branch chief Rakesh Maria.

'We will be producing the charge sheet before court within the stipulated timeframe (of 90 days).'

Police said they had asked a magistrate to visit the city police headquarters rather than transport the suspect, due to security concerns.

Iman, identified by Indian authorities as a Pakistani national, faces a string of charges including 'making war against the country' and murder.

He was one of 10 heavily-armed Islamist militants who killed 163 people across Mumbai, including at two luxury hotels and the railway station. -- AFP