Nelly Sindayen was the author of a Time article on a Feb. 23 meeting among several opposition figures allegedly involved in a plot to oust Arroyo.
Gonzales said Sindayen's testimony would help the National Bureau of Investigation to complete its probe into the Feb. 24 foiled coup attempt, which the government said included disgruntled troops, communist rebels and civilian backers.
Sindayen, a Philippine national, could not immediately be reached for comment, but earlier told colleagues that she was standing by her story, the AP reports.
Sindayen has been covering the Philippines for Time for decades, including the downfall of late dictator Ferdinand Marcos in 1986.
"Time stands by Nelly Sindayen and the story published in the magazine. We have nothing further to add at this time," Howard Chua-Eoan, Time's news director, said in an e-mail to The Associated Press.
The FSB of Russia has distributed the footage of video surveillance over suspects, who allegedly worked to orchestrate a military coup in Belarus and planned to assassinate its president, Alexander Lukashenko