Is the house in a very urban area? Is there any landscaping/grass or is it mostly sidewalk? How close is your house to your neighbors' houses? Are the storm sewers in good condition in your neighborhood? Does this happen all the time or only during very heavy rains?
The most likely cause is that water is not flowing away from your house when it rains. ...or maybe your neighbors are redirecting their runoff onto your property. ... or maybe the sewer pipes are clogged and excess water leaks out of them....
Find out if your neighbors have the same problem. Look at the outside of your house within about a 15 foot radius from where the seepage is occuring - to see where the water could be coming from.