Former Narcotics Control Bureau (NCB) Mumbai zonal director Sameer Wankhede on Sunday arrived at the Central Bureau of Investigation's (CBI) office in the city, for questioning in connection with a case related to the drugs-on-cruise case.Wankhede has been booked by the CBI for allegedly demanding Rs 25 crore as a bribe for not framing Bollywood actor Shah Rukh Khan's son Aryan Khan in the drugs-on-cruise case.Earlier on Saturday, Wankhede left the CBI office after five hours of questioning.