Jared Leto Accused of Inappropriate Behavior Toward Underage Girls in New Exposé

Jared Leto is being accused of inappropriate behavior via phone calls, emails and text messages with underage girls ... with the allegations coming out in a new report.

Air Mail -- a weekly newsletter founded by Vanity Fair's former editor-in-chief Graydon Carter and former New York Times reporter Alessandra Stanley -- published an exposé with accounts from several women who say they met him before they turned 18.

According to the report, a few of these women claim Leto asked for their phone numbers ... including one who says she was just 16 years old when he texted with her in 2006.

This anonymous woman says their talks quickly "turned sexual. He’d ask things like, ‘Have you ever had a boyfriend? Have you ever sucked a d***?’”

Model Laura La Rue told Air Mail she was 16 when she exchanged phone numbers with Leto in 2008 ... claiming she was just 17 years old when Leto allegedly walked around in front of her completely naked.

A third woman claims she began texting with Jared before she turned 18 ... and, he allegedly asked her "Do any of the little boys you hang out with f*** you?” when she was still underage.

This woman also claims Leto's alleged sexual overtones became more aggressive when she turned 18 ... claiming on one occasion he exposed himself to her and "started masturbating." She further alleged ... "Then he walked over, grabbed my hand, and put it on him. He leaned in and said, ‘I want you to spit on it.’”

Worth noting ... these accusers do not provide any physical evidence to support their assertions -- and, none of them are accusing Leto of engaging them in physical sexual activity before they turned 18 years old.

Leto's rep responded to the claims in the article ... telling Air Mail there is no truth to any of the allegations against him.