The Mumbai Police on Wednesday initiated an investigation into four complaints filed against Narcotics Control Bureau zonal chief Sameer Wankhede, The New Indian Express reported. Mumbai Joint Commissioner of Police Vishwas Nangre Patil issued an order of inquiry.

One of the complaints has been filed by Prabhakar Sail, a witness in the Mumbai cruise ship drugs case in which Aryan Khan, son of actor Shah Rukh Khan, is one of the accused. On Sunday, Sail had alleged that he had overheard private investigator Kiran Gosavi, another witness in the case, talk about a Rs 18 crore deal, of which Rs 8 crore was to be paid to Wankhede.

All four complaints filed against Wankhede are related to allegations of bribery, according to India Today.

A four-member team of the Mumbai Police will investigate the complaints. The team includes one officer each from Mumbai’s Azad Maidan and Colaba police stations. An officer from Mumbai Police’s Anti-Narcotics cell and one from the Cyber cell are also part of the team.

Wankhede is already facing a vigilance inquiry ordered by the Narcotics Control Bureau. The inquiry was initiated after Sail filed an affidavit detailing the allegations.

On Wednesday, a team of the Narcotics Control Bureau questioned Wankhede for four hours. The team has also issued summons to Sail and Gosavi, according to The Indian Express.

However, the anti-drug agency’s Deputy Director General Gyaneshwar Singh said that Wankhede will continue to remain the investigating officer in the cruise ship drugs case unless substantial evidence is found against him, ANI reported.

Aryan Khan and seven others were arrested by a Narcotics Control Bureau team led by Wankhede after a raid on a cruise party off the coast of Mumbai on October 2. The agency said it had seized 13 grams of cocaine, 5 grams of mephedrone, 21 grams of charas, 22 pills of MDMA (ecstasy) and Rs 1.3 lakh from the ship.

The hearing of the bail plea of Khan will continue on Thursday. His lawyers have repeatedly argued in courts that no drugs were found in his possession during the raid.

Since the raid, Wankhede has faced several allegations, most of them leveled by Maharashtra minister Nawab Malik.

The Nationalist Congress Party leader has accused Wankhede of being part of an extortion racket linked to drug-related cases against Bollywood actors. He has also claimed that Wankhede used forged documents to get his job under the Scheduled Caste quota and that he has been illegally tapping phones.

However, Wankhede has denied the allegations.

On Monday, he had filed an affidavit in a Mumbai court claiming that he was under a “lurking threat of arrest as it does not suit some vested interests for conducting an honest and impartial investigation”.

He also contended that Malik was targeting him as he had earlier arrested his son-in-law Sameer Khan.