A witness told the Scottish Child Abuse Inquiry hearing in Edinburgh he was 11 when he was forced to migrate overseas in the 1950s.
He was then sexually abused by priests at the care home he was moved to in Tasmania, the inquiry was told.
The man accused the British government at the time of robbing him of a family, a country and an education.
The evidence was heard as the probe in Edinburgh continues examining four children’s homes, including one in Lasswade, that are no longer operating.
The homes were run by the Catholic congregation the Sisters of Nazareth in Scotland.
Christopher Booth, 77, who waived his right to anonymity, said he was admitted to Nazareth House in Aberdeen at the age of ten in 1951 – a place where he described the regime as “brutal”.
He said he was there for about seven months before he was sent to Australia as a child migrant in 1952.
Mr Booth told how a nun informed him of the move, telling him: “Your family doesn’t want you, your country doesn’t want you. You’re just garbage.”
Mr Booth said he was given a “thrashing” after a relative went to the home to complain about him being moved overseas and said his mother later told him she had “not agreed to send me to Australia”.
He described how he was sent with a group of children from elsewhere in the UK to Australia and he was then taken out to Tasmania. Nobody showed him where Australia was on a map, he said.
The witness said he was sexually abused by priests in Australia, saying the abuse was “constant” and made him feel ashamed.
Mr Booth also told of receiving a “thrashing” from a priest, saying they “all had their choice of weapon” such as a cane or leather strap.
He said of the British authorities at the time: “I was born a Scotsman. When I was sent to Australia I was robbed of a family, I was robbed of a country, I was robbed of an education.”
Asked about his earlier time at Nazareth House in Aberdeen, Mr Booth told of regular thrashings at the hands of nuns using canes.
Children would be hit “until you cried”, he said.
“They were very happy to see if they could break you,” he told the probe.
Asked why the thrashings were dished out, he replied: “Looking back with hindsight now, I think they enjoyed it. I think they looked forward to some of the boys breaking the rules.”
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