Ronnie Radke Says FBI Involved in Brittany Furlan Catfishing Claims Amid Tommy Lee Split

Ronnie Radke is doubling down on his denial of having anything to do with Tommy Lee splitting with Brittany Furlan ... and he says the FBI got involved after Brittany claimed she got catfished by someone posing as Ronnie online.

We got the Falling In Reverse singer at Beachwood Cafe in Los Angeles on Tuesday and our photog asked him about Brittany claiming the alleged catfish caused major problems in her marriage to Tommy.

Ronnie tells us he's never talked to Brittany and has tons of love for Tommy ... and he'd heard others may have been catfished by the same impersonator.

He also revealed the FBI came knocking ... he told them his side of the story and was assured the feds would find out who was behind the account that allegedly catfished Brittany.

Ronnie sounds pretty fed up with the whole situation ... fans have been blowing him up about what happened and he's issued some denials on social media ... and he tells us he wants to put this behind him for good.