James Uthmeier said on X on Tuesday that he had instructed his office to execute search warrants and issue subpoenas related to the investigation.
The Tate brothers, who entered the United States last week, are also under investigation in Romania for alleged human trafficking and exploiting young women.
"Florida has zero tolerance for people who abuse women and girls. We will not allow it," Uthmeier said.
The brothers, who were arrested in Romania in December 2022, were initially restricted from leaving the country.
However, Romanian authorities eventually permitted their departure and the brothers travelled to Florida.
Speculation has circulated that the release was influenced by the US administration under President Donald Trump.
Trump has denied any involvement, stating last week that he knew nothing about the brothers' release and declining to answer questions regarding potential intervention.
Andrew Tate, a former kickboxer, has become a torchbearer for online misogyny in recent years, with Tristan assisting him.
In Romania, prosecutors accuse the pair of coercing women into producing explicit commercial sex videos.
Investigations have revealed at least 34 alleged victims, including a 15-year-old girl. Both brothers deny all charges.
