EXCLUSIVE

2:00 PM PST -- An attorney for Keelan Dadd tells TMZ "Mr. Dadd had no involvement whatsoever in this incident. Several weeks ago, he voluntarily met with detectives when requested to do so. After being apprised of the allegations against him and expressing his innocence, Mr. Dadd was arrested by Detective Flores of the Los Angeles Police Department. Mr. Dadd’s attorney, Anthony Willoughby, contacted Detective Flores and articulated that he could provide authorities with objective evidence proving that Mr. Dadd was not present during any of the alleged events. Instead, in a miscarriage of justice and Mr. Dadd’s due process rights, Detective Flores stated that regardless of any objective evidence, he would proceed forth with presenting the case to the District Attorney."

12:30 PM PST --﻿ An attorney for Steven tells TMZ the 15-year-old was victimized by the other adults involved much like the alleged victim was taken advantage of. He says Barajas and Dadd preyed on Steven's celebrity status and not all of the facts of the investigation have been laid out.

7:45 AM PST --﻿ According to the LAPD -- an investigation began last month -- the alleged victim told cops Fernandez lured her into a car, promised to introduce her to celebs and give her an appearance on his non-existent MTV show. Fernandez and Barajas were arrested during a sting by detectives just a few days later who pretended to be the 12-year-old girl and arranged a meeting through text messages at an abandoned house for sex. Dadd later turned himself in. Cops are still looking for more possible victims.

15-year-old YouTube star and skateboarder Steven Fernandez was arrested Wednesday after cops say he used his celebrity status to sexually exploit an underage girl.

Law enforcement tells TMZ ... Fernandez met a 12-year-old girl in his hometown of Compton last month and allegedly promised he'd introduce her to big name celebs in exchange for sexual acts. We're told the girl agreed and a sexual act was committed.

Cops were alerted shortly after and LAPD officers arrested Fernandez and 2 adults -- his manager Jose Barajas and another skater, 27-year-old Keelan Dadd. We're told all 3 were booked for sexual exploitation of a 12-year-old.

Steven's gained a huge social media following. In one of his videos ... Fernandez uses pickup lines on women. The video is unrelated to the arrest.