MARICOPA, Ariz. -- A Verizon senior engineer was arrested Wednesday on suspicion of having sexual relations with a 15-year-old girl over a six-month period, Pinal County sheriff's deputies said.

Greg Andersen, 45, of Maricopa, was booked into the Pinal County Jail on charges of sexual conduct with a minor, stalking and exploitation of a minor. A search warrant was served on his home outside of Maricopa.

Deputies said the girl reported that Andersen also took nude photographs of her and then placed some of the photos on a Web site.

The victim said that she recently returned a cell phone Andersen had bought her, left the state and obtained another cell phone that Andersen would not have the number for, deputies said. However, Andersen was able to get her new phone number, which was also a Verizon number, sheriff's investigators said.

While the victim was out of state, Andersen purchased a car and told the victim it was for her, deputies said.

He also reportedly asked the victim to marry him on different occasions, though Andersen is currently married, investigators said.

Deputies said the case is an ongoing investigation and additional charges may be pending.