Mumbai, Nov 8 (IANS): Amid a potential fresh threat, the Mumbai Police on Monday beefed up security for the family of industrialist Mukesh Ambani at his residence Antilia in south Mumbai, official sources said.

The move came after a taxi driver alerted the Mumbai Police after overhearing two suspicious persons who were reportedly collecting certain information on Antilia.

The police have detained the taxi driver to record his statement, prepare a sketch of the two 'mysterious' persons, and scouring the CCTV footage of the route on which they commuted.

Road blocks have been erected at various strategic locations in Mumbai to help track the two unknown persons, who were reportedly carrying a couple of bags, as per the taxi driver's statement, though the police declined to share further details.

Simultaneously, security has been further tightened with a dog squad, a Rapid Action Force team and more personnel outside Antilia, the residence of the Reliance Industries Ltd Chairman and his family.

Official sources hinted that after making preliminary enquiries, Mumbai Police are likely to issue a formal statement in the sensitive matter.

Antilia was previously targeted on February 25 when an abandoned SUV with 20 gelatin sticks and a threat note was found near the building, sending the police into a tizzy besides kicking off a national uproar sparking global concerns.