Your phone can only legally be tapped by law enforcement, who must show probable cause for tapping the line. Police have the technology to tap both landline and cell phones. If you think your phone is being tapped, you can get the answers you need from your cell phone provider or from the legal system.
Call your phone company and let them know that you are worried that your phone may be tapped. The phone company will take the steps to inspect your line.
Call your phone company again if more than 48 hours have passed since your last call. If there is an illegal tap on your phone, your phone company will remove it. If there is a legal tap on your phone, however, the phone company is not authorized to inform you or to remove it.
Contact the police if there is an illegal tap. They will start an investigation to find out who put the tap on your phone and possibly bring charges.