Police on Monday arrested a youth who sent threatening messages to Bollywood actor Amitabh Bachchan.Devi Singh Rajpurohitthan was arrested by Mumbai Crime Branch officials for sending a threatening message to Bachchan for sum of Rs 25 crores.In the SMS, Rajpurohit demanded to pay him a ransom of Rs 25 crore, Joint Commissioner Maria said.The police told that he had shot for some scenes of the soon-to-be released movie ‘Drona’ k Bachchan.According to Rajpurohit, many of his villagers had told him that he should start acting in movies, Maria said.Rajpurohit used to send messages using his own mobile number through which he was tracked and arrested, he added.