Somaiya has been demanding that Uddhav declare his financial assets and has alleged the Sena leader has links with shell companies indulging in money laundering.
Pradhan, who stays at Parel in Central Mumbai, submitted a written complaint to Shivaji Park Police Station, a police officer said.
According to the complaint, Pradhan received threat from Somaiya's former personal assistant Dayanand Nene after the former's post on the 'Alert Citizen Forum' WhatsApp group about distribution of sarees and money allegedly from Somaiya's vehicle, to lure voters.
Nene later posted "Harshal, let's confront once, will die or kill, place and time of your choice." Pradhan mentioned this in the police complaint.
"We have forwarded this complaint to Bhoiwada Police Station," senior PI Gangadhar Sonawane of the Shivaji Park police station said.
"When Pradhan is at his home, we will protect him. So we have sent back his application to Shivaji Park Police Station for further action," Dattatray Patil of Bhoiwada Police Station said.