The fire broke out shortly after midnight at a facility operated by WB Electronics, part of the WB Group, one of Poland's largest private defence companies and a major producer of drones.
The blaze destroyed warehouse space and caused damage estimated at around PLN 15 million (EUR 3.5 million, USD 4 million), prosecutors said. Those convicted of the offences could face life imprisonment, they added.
No one has been charged in the case so far.
The investigation is being conducted jointly with Poland's Internal Security Agency (ABW) and police in the south-central Świętokrzyskie province, state news agency PAP reported.
The fire engulfed a warehouse and production hall, and firefighters took about two hours to bring it under control, according to interior ministry spokeswoman Karolina Gałecka.
The facility was closed at the time and no employees were inside, she said.
A thermal imaging camera was used after the fire was extinguished, but no chemical substances were detected, Gałecka said. No one was injured.
Police secured the site and immediately began investigating the cause of the fire, said Anna Sławińska, a police spokeswoman in Skarżysko-Kamienna.
Officers were using modern technology to examine the scene, she said.
WB Group said the fire broke out at one of its facilities but described it as a "small fire."
The company said all safety procedures and systems had worked properly and that the blaze was quickly put out.
The company thanked firefighters and employees who assisted with the emergency response and said the facility would resume operations after formal procedures were completed.
Jacek Dobrzyński, spokesman for the government minister in charge of security services, urged caution against spreading unverified claims about the cause of the fire.
"Various narratives are forming, and some people are already describing how this happened," he said. "All of this will now be thoroughly clarified."