The Coahuila State prosecutor's office said it had interviewed the five workers who managed to escape from the mine.
"Apparently they were expelled by a torrent of water," Coahuila attorney general Gerardo Marquez told the press.
He added that his office had requested information from the landowner and mine concession holder, but declined to name them.
Experts detected a leak coming from nearby mines and were trying to find its exact location so they can stop water from flowing into the area where the workers are trapped, Coahuila's labor secretary, Nazira Zogbi, said on Saturday.
A French company has provided equipment to assist in the task, she said, without naming the firm.
Coahuila, Mexico's main coal-producing region, has seen a series of fatal mining accidents over the years.
Last year, seven miners died when they were trapped in the region.
The worst accident was an explosion that claimed 65 lives at the Pasta de Conchos mine in 2006.
Only two bodies were retrieved after that tragedy.