Rehab singer Amy Winehouse's jailed husband has been allegedly begging her to secretly fund his drug habit in the big house.Blake Fielder-Civil, 25, is currently locked up in London’s Pentonville Prison but is still tying to smuggle heroin into the establishment, reports the British newspaper The Sun. According to the publication, Fielder-Civil has asked the singer to make payments to another prisoner in a bid to fund his habit behind bars. And Pentonville’s head of security Andy Watts is already suspicious of the plot. He has written to Fielder-Civil’s lawyers, warning, "There is a strong and supported intelligence he is involved in attempting to smuggle drugs into the prison." Fielder-Civil has pleaded not guilty to charges of attempting to pervert the course of justice and will stand trial this June. The 25-year-old is accused of attempting to fix the outcome of a previous trial for grievous bodily harm.