"We have issued a lookout notice against Narayan Sai, son of Asaram," Surat Police Commissioner Rakesh Asthana said.
"We have informed immigration authorities that a grave offence has been registered against him. This (lookout notice) is a precautionary step so that he cannot leave the country," Asthana said.
Police teams have started investigation in the case and Sai is being traced, he said, adding that they have identified a few locations where he could be.
Yesterday, Asthana had said that they will interrogate Sai regarding the complaint. Fresh sexual assault complaints were registered here yesterday against controversial Asaram and his son Narayan Sai here after two sisters accused the duo of abusing them.
Asaram, 75, was arrested in August on charges of sexually assaulting a minor girl and has been in prison at Jodhpur in Rajasthan since then.
Police registered two complaints - one against Asaram and another against Narayan Sai - of rape, sexual assault, illegal confinement and other charges. The complaint against Narayan Sai was registered at Jhangirpura police station in Surat, while the one against his father Asaram was transferred to Ahmedabad as the alleged incident happened there.
The elder sister in her complaint accused Asaram of repeated sexual assault between 1997 and 2006, during the time she had been living in his ashram on the outskirts of Ahmedabad city. The younger sister filed a complaint against Asaram's son, accusing him of repeated sexual assault between 2002 and 2005 when she was living in their Surat ashram.