Philippine officials say that years of disaster-preparedness drills helped prevent a larger casualty toll when one of the strongest earthquakes in 50 years struck the south and left 55 people dead with 31 others still missing
The charges come as the firm is involved in a defamation suit against Fox News.
The powerful quake was recorded at 9:59 p.m. local time on Tuesday.
Duterte was detained as he returned to Manila on Tuesday, officials said.
One U.S. military service member and three defense contractors were killed.
The voting machine company executives allegedly paid $1 million in bribes.
