LINCOLN — Lt. Gov. Rick Sheehy resigned his post abruptly Saturday after questions were raised by The World-Herald about improper cell phone calls to four women, other than his wife, during the past four years.

An investigation by The World-Herald discovered that Sheehy made about 2,000 late-night telephone calls to the women on his state-issued cell phone, many of them long conversations held in the wee hours of the night.