MANILA - (UPDATED) State forces discovered Monday at least P79 million in cash and checks in a house in Marawi City after retaking a stronghold of the Maute fighters they have been battling since last month.

The Philippine Marines first found P52.2 million in cash at a house located near the extremists' machine gun nest in the Mapandi area.

Of this amount, P52 million was wrapped in plastic bundles while P200,000 was stashed in envelopes.

After clearing a machine gun nest of the Maute Group, Marines found P52M in cash at a nearby house in Mapandi | via @chiarazambrano pic.twitter.com/DfW2OotI1U

— ABS-CBN News (@ABSCBNNews) June 5, 2017

The troops then found checks worth P27 million in the same house, bringing the total amount of the haul to P79 million.

Authorities said the owner of the house was likely among the 200,000 residents who fled from Marawi after Maute and other bandit groups attacked the city on May 23.

Investigators are now looking into the cash and check's paper trail to confirm if the money is connected to terrorist operations.

President Duterte earlier said that Maute terrorists are being funded by foreign terror groups and illegal drug money.

The fighting in Marawi has prompted Duterte to place the entire Mindanao island under martial rule.

A presidential spokesman said 120 militants have died in the battle, along with 38 government forces. The authorities have put the civilian death toll at between 20 and 38.