maytag neptune washer slowly fills with water between uses

Hi, We have a Maytag Neptune washing machine and when we don't use it for several days, water begins pooling in the bottom of the rotating drum. So far we haven't had a problem with it overflowing but it seems like if it gets worse or if we were to go on vacation for several weeks, it could eventually overflow onto the floor. My wife says it has been getting worse over time. Over a day or two it got about 2 inches deep. Anybody else have this problem or know of a solution? Thanks