Immigrants were taken from a Mission home around 1:40 this afternoon.
Border Patrol agents said the 48 immigrants are from Mexico, Honduras, and Guatemala.
It is unknown exactly where they were headed.
Articles of clothing, gallons of water, and leftover food are all indications that it was a stash house.
Agents said they received a call about suspicious activity happening at 601 Thornwood Drive.
After investigating, they say they had enough evidence to go in and search the property.
San Juan police say stash houses, like the one discovered in Mission today, are the reason they have created a stash house taskforce.
They assign two full-time officers to identify the growing stash house problem.
The way stash houses are discovered is an increase number of people enter and leave homes at all hours of the night and more trash piles up around the home.
Police officers said many times smugglers will rent out homes and never hook up the electricity or water.
They often keep a close eye on new activity in neighborhoods.
Police are unaware of just how many days the immigrants had been hiding out in the home.