Sameer Wankhede visited the NCB's headquarters in New Delhi on Tuesday.
The NCB's Deputy Director General (DDG)-northern region, Gyaneshwar Singh, who is heading the departmental vigilance probe into allegations of extortion in the drugs-on-cruise case, arrived at the agency's office here on Wednesday.
Mr Singh reached the Narcotics Control Bureau's (NCB) office at Ballard Estate in south Mumbai at 12.45 pm.
The NCB has ordered a vigilance inquiry into the claims made by a witness, Prabhakar Sail, in the cruise drugs case of an extortion bid of Rs 25 crore by some agency officials, including its Mumbai zonal director Sameer Wankhede, to let off Aryan Khan, the son of Bollywood superstar Shah Rukh Khan.
The inquiry is being conducted by Gyaneshwar Singh, who is also the chief vigilance officer of the federal anti-narcotics agency.
A large number of media persons were present outside the NCB's office when Mr Singh arrived.
While getting out of his vehicle, Mr Singh said he will speak to media persons later.
It was not immediately clear whether he will record the statement of Wankhede on Wednesday.
Mr Singh along with four other officers of the NCB landed in Mumbai from Delhi in the morning.
Mr Wankhede, who is leading the probe in the cruise drugs case, visited the NCB's headquarters in New Delhi on Tuesday and spent over two hours.
Sources earlier said the inquiry will also look at the aspect of K P Gosavi, another NCB independent witness in the case, being in close proximity of Aryan Khan after the raids, and the procedures followed by the sleuths while entrusting custody of all the accused arrested on October 3 from the international cruise terminal in Mumbai.
Photos and videos of Mr Gosavi with Aryan Khan have gone viral on social media and other news platforms.
The role of all the officers and witnesses involved in the case will be probed and it will be recorded if they followed the NCB manual and procedures mentioned in the Narcotic Drugs and Psychotropic Substances (NDPS) Act during such operations, they said.
Mr Wankhede on Sunday wrote to Mumbai Police commissioner Hemant Nagrale, seeking protection from likely legal action "being planned" against him by unknown persons to falsely frame him concerning an alleged vigilance-related issue.
On Monday, he failed to get any relief related to an affidavit on the sensational extortion claims made by Mr Sail, with a special court saying it cannot pass a blanket order barring courts from taking cognisance of the document.