A court on Wednesday sent Iqbal Kaskar, the brother of underworld don Dawood Ibrahim, to police custody till February 6.
The Mumbai Police had earlier on Tuesday arrested Kaskar and two of his associates on charges of extortion following a complaint by city-based real estate agent Salim Shaikh.
Shaikh had alleged that Kaskar and his associates demanded Rs three lakhs from him, following which he was thrashed.
Following the complaint, an FIR was registered at the Byculla Police Station on Monday night, after which the case was transferred to the J J Marg Police Station, from where Kaskar was arrested.
Kaskar had been deported to India from Dubai in 2003.