Myanmar’s suffocating control of its Rohingya population amounts to "apartheid", Amnesty International said Tuesday in a probe into the root causes of a crisis that has sent 620,000 refugees fleeing to Bangladesh.

Distressing scenes of dispossessed Rohingya in Bangladeshi camps have provoked outrage around the world, as people who have escaped Rakhine state since August recount tales of murder, rape and arson at the hands of Myanmar troops.

Myanmar and Bangladesh have agreed in principle to repatriate some Rohingya but disagree over the details, with Myanmar’s army chief saying last week that it was "not possible" to accept the number of refugees proposed by Dhaka.

The Amnesty report, published Tuesday, details how years of persecution have curated the current crisis.

A "state-sponsored" campaign has restricted virtually all aspects of Rohingyas’ lives, the Amnesty study says, confining them to what amounts to a "ghetto-like" existence in the mainly Buddhist country.

The 100-page report, based on two years of research, says the web of controls meet the legal standard of the "crime against humanity of apartheid ".

"Rakhine State is a crime scene. This was the case long before the vicious campaign of military violence of the last three months," said Anna Neistat, Amnesty’s Senior Director for Research.

Myanmar’s authorities "are keeping Rohingya women, men and children segregated and cowed in a dehumanising system of apartheid ," she added.

The bedrock for the widespread hatred towards the Muslim group comes from a contentious 1982 Citizenship law.

Enacted by the then junta, the law effectively rendered hundreds of thousands of Rohingya stateless.

Since then, Amnesty says a "deliberate campaign" has been waged to erase Rohingya rights to live in Myanmar , where they are denigrated as "Bengalis" or illegal migrants from Bangladesh.

A system of identification cards is central to those bureaucratic controls, and likely to form the basis of the decision on who will be allowed to return from Bangladesh.

The latest wave of persecution has pushed more than half of the 1.1-million strong minority out of the country, with those left behind sequestered in increasingly isolated and vulnerable villages.

Although the Rohingya have been victims of discrimination for decades, the report details how repression intensified after the outbreak of violence between Buddhist and Muslim communities in 2012.

Long before the recent mass exodus of Rohingya from northern Rakhine state -- now a virtual ghostland of torched villages and unharvested paddy fields -- they were unable to travel freely, requiring special permits and facing arrest, abuse and harassment at numerous checkpoints.

In central Rakhine state, Rohingya Muslims were driven out of urban areas after the 2012 violence.

They remain completely segregated from the Buddhist community, confined by barbed wire and police checkpoints to camps that Amnesty calls an "open-air prison".

The Muslim community is widely denied access to medical care, their children are unable to attend government schools while many mosques have been sealed off.

"Restoring the rights and legal status of Rohingya , and amending the country’s discriminatory citizenship laws is urgently needed," said Anna Neistat.

"Rohingya who have fled persecution in Myanmar cannot be asked to return to a system of apartheid ."