A Medford man has been ordered held on $25,000 cash bail on charges he stole millions from a former employer.

George Papadopoulos pleaded not guilty Tuesday in Suffolk Superior Court on larceny and procurement fraud charges.

Prosecutors said the 48-year-old stole $3 million while vice president of URS Corp., a Salem, N.H.-based global construction management company with offices in Boston’s Financial District.

He is also accused of stealing $15,000 from STV, a New York engineering company.

Court documents show Papadopoulos fraudulently billed URS for millions in expenses and covered up the thefts by altering bills sent to clients, including Massachusetts Port Authority and Harvard University.

His attorney, Robert Delahunt, did not return a call seeking comment.