The Independent Inquiry into Child Sexual Abuse is to hold its first public hearings today after lengthy delays.

The inquiry, which was announced in 2014 to investigate wide-ranging historic child abuse offences, is expected to last around five years. A report containing recommendations will be published at its conclusion.

As of February 2017, the inquiry is on its fourth chairwoman and has cost £23.6m after a series of top-level resignations over its three-year existence.

It will be split into public hearings regarding different areas of concern, starting today with an investigation into cases of British children sent abroad by the British government between the 1920s and 1960s.

Professor Alexis Jay, the current chair of the inquiry, will listen to evidence about the abuse of child migrants who were shipped to Commonwealth nations such as Canada and Australia.

The victims were part of a larger programme that oversaw as many as 150,000 children, aged three and upwards, who were taken from their families after World War II, reports The Guardian.

"They were recruited by religious institutions from both the Anglican and Catholic churches, or well-meaning charities, including Barnardo's and the Fairbridge Society, with the aim of giving them a better life," says the BBC. Up to 10,000 children were sent to live in Australia. A 1998 government report found that many of the children suffered physical and sexual abuse in homes and schools run by charities and religious groups.

Clifford Walsh, now 72, told the BBC that he was raped and beaten at one Catholic institution. "We had no parents, we had no relatives, there was nowhere we could go, these brothers – these paedophiles – must have thought they were in hog heaven," he recalled.

Another survivor, Lynda Craig, who was sent to Fairbridge Farm school at the age of five, told The Guardian that young children suffered "insurmountable hardship" that could be described as slavery.

The Australian government officially apologised in 2009. The UK government followed suit in 2010.

The overall inquiry is also investigating claims against a wide range of institutions in the UK, including local authorities, the police, the BBC, the armed forces, schools, hospitals and children's homes.