The former founder and chief executive officer of an Arlington technology firm has pleaded guilty to paying off a federal agency employee to help his company obtain $4.5 million in contracts.

A niece of the unnamed Federal Deposit Insurance Corporation employee worked for Irving Gilmore Rodrigues at Avalon Technology Inc., and helped Rodrigues transfer about $134,000 to her uncle, prosecutors wrote in court documents filed in Alexandria’s federal court Tuesday. Rodrigues admitted to paying only $16,134.