The body of a pedophile priest, who was forgiven by the Catholic Church after he admitted to raping 26 children, was found in his Massachusetts home after being stabbed to death.

His body was found bound and gagged by his brother after he missed a scheduled Mass at a church, according to police records.

Police believe he had been tortured before he died by "more than one assailant", who had stabbed him several times in the chest and also "removed" his genitals.

He is believed to have died of his injuries after a "very large blade" - most likely a machete - was inserted into his rectum in its entirety, fatally damaging several of his internal organs.

Father Archambault was accused of abusing 29 children on multiple occasions with victims ranging from 5 to 11-years-old.

The Roman Catholic Diocese of Springfield received a number of complaints against the priest prompting an investigation by the Vatican under Canon law.

Of the 29 complaints, the church only investigated 26 of them after deciding there wasn't enough evidence to pursue 3 of the claims.

Due to the Catholic Church's internal investigation protocols, the case was tried under Canon law which operates outside of the boundaries of the regular law.

The Vatican decided this was a church matter, telling families there was "no need for the police."

Father Archambault admitted to the remaining charges from 26 victims but claimed that he didn't rape them as "they all consented to it."

Despite the youngest child being just 5-years-old, the Cannon court accepted that the children consented to sex with the 42-year-old priest and ruled that he didn't rape them.

Although he wasn't charged with child abuse, the judge declared that having sex with all those children was a "grave sin" and "must not go unpunished."

As "punishment" for his crimes, the priest was forced to take paid leave and was sent to a retreat in Alabama for a month to seek forgiveness through "prayer and penance."

He was killed shortly after returning from the retreat.

Families of the victims were outraged by the church's handling of the case and tried to launch an appeal by writing a joint letter to the Pope in the hope the case could be turned over to law enforcement.

They didn't receive a reply from Pope Francis, but did get a letter back from the church telling them that the "case is now closed."

A police spokesperson said they are "following leads" in the case of Archambault's death and believe the killing may be the work of vigilantes responding to the child abuse claims.

A statement released by the diocese said the Catholic Church expects the "full force of the law to be used" in bringing the priest's killers to justice.