A professional gang had dug a hole in the terrace of the Law house with a crowbar over several days to carry out Tuesday’s robbery, the detective department claimed on Wednesday.

“The sound of digging got drowned in the noise from the College Street market reconstruction site,” said a senior officer of the detective department.

At least three youths were part of the gang. According to the cops, the gang members knew valuables were stored in the room that had been kept under lock and key for years.

A family member handed over a catalogue of items that were in the room to the cops on Wednesday.