Around a fifth of boys at Rubane House in County Down were subjected to sexual or physical abuse, according to a public inquiry.
In a report by the Press Association, former Royal Ulster Constabulary detective chief superintendent Eric Anderson wrote a note to the Director of Public Prosecutions.
It said: "Sexual abuse by a considerable number of the De La Salle brothers on the children and consequently between children is rampant."
Three De La Salle Order brothers were charged but none convicted after their trials did not go ahead due to legal issues.
Mr Anderson added: "The full horror of the abuse in this establishment is reflected in 41 files already submitted through your office to the DPP.
"I consider the complaints made to show it to be on a par with, if not worse than, the abuse at the Kincora children's home."
Kincora was the subject of a high-profile child abuse scandal in the 1980s. Three senior care staff at Kincora were jailed in 1981 for abusing 11 boys in their care.
Rubane was the subject of a police investigation in the 1990s, the Historical Institutional Abuse inquiry was told.
From 1951 until 1985 around 1,000 children stayed at Rubane, near Kircubbin on the Ards Peninsula. Abuse of around a fifth of residents ranged from watching boys in the showers for sexual gratification to rape or physical attacks, lawyer for the inquiry Joseph Aiken said.
Most of the alleged offenders are dead or medically certified unfit for trial.
Around 200 former residents made abuse allegations about Rubane, 55 have come forward to the inquiry and the majority are expected to give evidence. Lawyers are to examine 40,000 documents.
Alleged victims of paedophile priest Father Brendan Smyth are among those expected to give evidence.
Rubane was a voluntary children's home for boys aged between 11 and 16 but increasingly from the 1970s it accepted children from the welfare authorities, predominantly from deprived parts of Belfast. Some of the boys were 'educationally sub-normal', according to official documents read out during the inquiry.
The inquiry is expected to begin hearing evidence next month.