Former prime minister Gordon Brown has told the public inquiry into child sexual abuse that forced child migration programmes amounted to "government-induced trafficking".
Mr Brown was giving evidence as the wide-ranging investigation into abuse looks at what happened to children who were sent abroad as migrants between 1920 and 1974.
Most of the children from poor families or in the care were sent to Australia, Canada, New Zealand, and what was then Southern Rhodesia (now Zimbabwe).
The schemes involved 130,000 children and many are believed to have suffered physical and sexual abuse.
Mr Brown, who became first become aware of the issue in 2007, told the Independent Inquiry into Child Sexual Abuse (IICSA) the schemes were a "violation of human rights".
He also described them as the equivalent of a "modern form of government- induced trafficking".
In 2009, the Australian government apologised for the abuse experienced by child migrants.
Mr Brown, who issued a national apology to migrants in 2010, added: "Clearly, successive governments have failed in a duty of care."
"Children were denied a childhood, an identity, a family and any sense of belonging. Many, some as young as three, were sent abroad, often having been falsely told their parents were dead."
Brown: Scale of abuse "could be worse than Savile scandal"
Mr Brown said the abuse suffered by victims could be "the worst national sex abuse scandal in numbers, length of time unchecked and geographical scope".
He added: "The sheer scale of sexual abuse of British-born girls and boys could be worse than in the Savile scandal and further children's homes outrages we are aware of.
Former presenter Savile, who died in 2011, aged 84, was later unearthed as one of Britain's most prolific sex offenders.
Mr Brown also urged the inquiry to look at "why people like me were never told, why departments in government may have had some information but it was never transmitted."
The former prime minister also called for the surviving 2,000 victims of the transportation programmes to be compensated.
Earlier, former Conservative Prime Minister Sir John Major, also gave evidence in the form of a written statement read on his behalf.
Mr Major said he was made aware of allegations of physical and sexual abuse of a number of child migrants some years ago in Australia.
But he added that "very little information" on this issue was referred to him personally during his time as prime minister.
"I therefore have no informed opinion or knowledge to offer," he said.
Following the child migration hearings, the inquiry will go on to investigate abuse claims involving councils, religious organisations, the armed forces, and public and private institutions.