A refugee who raped a ten-year-old boy has claimed he did not know sexually assaulting the child was wrong as it was 'culturally acceptable' in his homeland.

Mufiz Rahaman told Sydney's Downing Centre Court raping children was not seen as morally wrong in his native Myanmar when he pleaded guilty to the aggravated sexual assault of a 10-year-old refugee on Wednesday, the Daily Telegraph reported.

The 20-year-old and his young victim are both stateless Rohingya Muslims - a group of people considered illegal immigrants from Bangladesh by the Buddhist-majority in Myanmar - who came to Australia to flee religious persecution.

A 20-year-old man who raped a 10-year-old boy says sexually assaulting children is acceptable in his home country of Myanmar (stock image)

The court heard Rahaman preyed on the young boy while he was living with a group of refugees, including his father, at a vacant RSL club in Lakemba, a suburb in Sydney's south west, on January 8, 2015.

According to documents tendered to the court, he crept into the child's bedroom - which he shared with his father - as he slept and took off the boy's underpants.

He then raped the boy, who arrived in Australia in 2013, while his father was in another room preparing lunch.

When the boy's father returned he noticed the door had been shut and overheard Rahaman tell the boy: 'I'll give you money for this.'

'My father will hit me,' the boy responded.

The boy's dad stormed into the room and found Rahaman lying on top of his son who was face down on the bed with his pants around his knees.

He asked: 'What are you doing to this little boy? You're an adult.'

Mufiz Rahaman appeared before a judge at the Downing Centre where he was sentenced to five years jail for the crime

The paedophile denied doing anything to his son but the young boy told his father he had been raped.

Rahaman, who came to Australia in 2012, was arrested two days later after another family member reported the incident to police.

He submitted to a DNA test which was matched with semen found on the victim.

According to the Daily Telegraph, Rahaman told the court he had been a victim of sexual abuse as a child before he moved to Australia.

Judge Andrew Scotting said Rahaman failed to understand his actions would 'physically' and 'psychologically damage' his young victim.

He also said Rahaman, who insisted he thought sexual assault was not seen as morally wrong in his homeland, had not accepted responsibility for his actions and demonstrated a 'lack of morality', according to the Daily Telegraph.

'There is a need for specific deterrence ... The offence appears to have been (viewed) as being culturally acceptable conduct in the offender's childhood,' Judge Scotting said.

Judge Scotting sentenced Rahaman to five years jail with a non-parole period of three years.

The 20-year-old will be eligible for parole in March 2018 - but the judge noted he had a moderate to high risk of re offending.

ROHINGYA MUSLIMS Rohingya Muslims are a group of people who have faced religious persecution at the hands of the Buddhist-majority in their native Myanmar. The Rohingya are often referred to as 'Bengali' in Myanmar, a term that implies they are illegal immigrants from Bangladesh, although Rohingya families have lived in the area for generations. They are not among the 135 ethnic groups recognised by law and are considered stateless as the country does not recognise their citizenship. Rohingya are prevented from moving freely and their access to healthcare and education is restricted. Many from the million-strong minority are unable to vote, have little working rights and are reviled as imposers by the Buddhist majority. More than 120,000 have been displaced, many to squalid displacement camps in western Rakhine state, after fleeing violence stirred by Buddhist nationalists in 2012, with around 20,000 homes destroyed. Thousands fled to other Southeast Asian countries on rickety boats in search of better lives, only to drown or fall victim to human traffickers. Some 25,000 Rohingya and economic migrants from Bangladesh boarded smugglers' boats between January and March 2015, almost double the number from the previous year Some 25,000 Rohingya and economic migrants from Bangladesh boarded smugglers' boats between January and March 2015, almost double the number over the same period in 2014. An estimated 300 people died at sea during this period as a result of starvation, dehydration and abuse by boat crews. Thousands of Rohingya and Bangladeshis were left stranded in the sea for weeks in May 2015 after Thai authorities cracked down on a popular smuggling route, sparking the Asian migrant crisis. Malaysia and Indonesia ended the impasse by agreeing to offer temporary shelter to the boat people on condition that a resettlement and repatriation process would be carried out within a year by the international community. In June, the UN said the Rohingya suffered entrenched discrimination so deep it may amount to crimes against humanity. Source: Reuters Advertisement