The Montgomery County District Attorney’s office has withdrawn charges against a pair of gamblers who have been in county prison since late march, when a construction crew dug up nearly a million dollars buried in the backyard of one man’s home in the Meadowbrook section of Abington Township. The county has turned the evidence over to federal prosecutors. 60-year-old Joseph Mastronardo and his 54-year-old brother and business partner John, of Blue Bell, remain at the county prison in lieu of $1 million bail each as they await their next court appearance. They still face charges for violating their probation from an earlier case. Their business was illegal betting on professional and college football and other sports. The latest charges come from a broad federal investigation into offshore and internet betting, and the buried money may have been part of the proceeds. Joseph Mastronardo’s wife of more than 30 years is Joanna, daughter of the late Philadelphia Mayor Frank Rizzo.