Detectives from Humberside Police have confirmed they are investigating two separate allegations made against Karl Foxhall, who was jailed in June for a string of sexual offences including the rape and abuse of a young boy.
As previously reported in the Mail, the 21-year-old, of North Newbald, was sentenced to six years and eight months in jail after admitting all six charges.
The Mail has now learned he is to be questioned over further allegations of sexual offences made to police following an appeal by his victim's parents.
Officers from the force's family protection unit are investigating the claims.
The Mail understands the allegations relate to dates prior to the offences he was jailed for.
A spokesperson for the force said: "Investigations are ongoing into two allegations which have been made.
"Humberside Police take all such allegations seriously.
"At this stage of the investigation, it is inappropriate for us to comment further."
Foxhall was jailed after pleading guilty to charges of being in possession of 72 images of indecent photographs, causing a child to watch a sex act, two offences of sexual assault, sexual activity in the presence of a child and rape.
After he was sentenced, the parents of his victim, who cannot be identified for legal reasons, told the Mail they believed Foxhall may have abused others and urged people to come forward.
Speaking at that time, his father said: "I do believe there will be more. If more victims come forward they can at least get the help they need, instead of living with it on their own."
The couple also said they were devastated with the sentence handed to their son's abuser.
His father said: "We just felt totally deflated. He is going to be out in just over three years. We were devastated – really angry."
The boy's mother said: "Even if he had got 20 years, it wouldn't have been enough in our eyes, but for the sentence to be as low as six is an insult."
Victims of sexual assault can report it to the Care After Sexual Assault Suite at 810A Hessle Road, Hull, or call (01482) 305037.
Survivors (Hull and East Riding) offers counselling to victims of sexual abuse and can be contacted on (01482) 226677.