It's hard to conceptualize but imagine a river flowing 13,000 feet below the Amazon. That is what scientists have discovered: a gigantic underground water body thousands of feet below the world's second longest Amazon River.

Researchers from Brazil's National Observatory have found results indicating to a subterranean river 6,000 kilometers long, almost the same length as the Amazon directly above it, the Associated Press reported.

The body of the water has been named after Valiya Hamza who led the research and found that the Amazon rainforest has two separate drainage systems: the surface drainage through the Amazon and the flow of groundwater through the deep sedimentary layers, the Hamza.

The information has come from 241 inactive oil wells drilled by the Brazilian oil company, Petrobras, according to Valiya Hamza, head of the research team from the observatory. Thermal information provided by Petrobras has allowed Hamza and his team to identify the movement of water 13,100 feet below the Amazon River.

Computer simulations show that the groundwater flow is predominantly vertical to about 2,000 feet deep, but changes direction and becomes horizontal at greater depths.

According to the researchers, the presence of the Rio Hamza River might account for the relatively low salinity of the waters around the mouth of the Amazon.

Hamza has stated that the studies are still in their preliminary stage but he aims to confirm the subterranean flow of water by the end of 2014.

As the second largest river in the world, the South American Amazon River has the largest drainage basin in the world, approximately one-fifth of the world's entire river flow.