The 54-year-old actor is the subject of a new BBC documentary, Jared Leto: Hollywood's Dark Secret, in which four women accuse him of criminal sexual conduct and allege the offences took place when they were teenagers.
Leto hadn't responded to multiple attempts to contact him for the BBC program, but has now issued a statement to People magazine in which he made his stance clear.
He said: "I have never sexually assaulted anyone in my entire life. These claims are absolutely and categorically false."
In the documentary, one woman claimed she was sexually assaulted in a motel bathroom when she was 17, while another accused the Dallas Buyers Club actor of threatening her with sexual assault when she was unexpectedly left alone with him in a hotel room aged 19.
A third, identified in the program as Clara, alleged Leto had "shrugged off" a conversation about the age of consent being 18 in California when he had sex with her at the age of 17, and claimed he asked her to call him "Daddy" while pretending to be a "little girl" or "my little girl".
A fourth woman claimed he had groomed her, using his celebrity status to make repeated sexually-explicit phone calls to her when she was just 16, and suggested at least once that they should have sex.
The latter accuser was sent a non-disclosure agreement (NDA) to prevent her from talking about their relationship, which has been seen by the BBC, but she refused to sign it.
Another woman, identified as Alex, was 19 when she met the rocker but "felt the need" to pretend to be younger in order to protect herself - but she alleged Leto was dismissive when she told him she was 17.
She claims he said: "Age is just a number, and anyway, we're in Europe."
Four other women in the documentary described receiving strange and typically very sexual phone calls from the star when they were younger, while one female recalled how her mother confronted the star after he instructed a security guard to take her backstage at a music festival, having made a lewd comment towards the then-14 year old during an autograph signing.
Documentary makers corroborated a number of the women's accounts with their friends and family who were told at the time, and also saw pictures and messages that backed up some of the stories.
According to the BBC, more than 120 allegations have been made online concerning the Leto's behaviour towards women.
