Probes into six cases, including the alleged drugs haul in which Shah Rukh Khan’s son Aryan is an accused, have been transferred from the Mumbai zone of the Narcotics Control Bureau (NCB) to the agency’s headquarters in Delhi.

The move came amid allegations of extortion against the NCB’s Mumbai zonal director, Sameer Wankhede, who was supervising the drugs case probe. The NCB reports to the Union home ministry.

Officials cited “wider and inter-state ramifications” as the reason for the shift. But another section said the objective was to deflect attention from the charges against Wankhede, which were affecting the probe’s credibility.

Wankhede denied he had been “removed” from the investigation in the Aryan case, PTI reported.

At least 26 cases have come under a cloud following a disclosure in a purported letter from an unnamed NCB officer to Maharashtra minister Nawab Malik.