Aust model illegally in US: ICE says

Peter Mitchell, AAP US Correspondent
Australian-South Sudanese model Adau Mornyang arrives for her court case in Los Angeles in July

US immigration officials are sticking by their decision to arrest Australian model Adau Mornyang and keep her locked up for more than two months.

Mornyang, 25, was deemed "illegally present" in America after a judge in Los Angeles sentenced her to probation and community service in July for assaulting and interfering with a flight attendant on a "nightmare" Melbourne to Los Angeles United Airlines flight.

Mornyang's sister, Maria, claims the model had a valid visa and was in the US legally on September 17 when she was arrested in a "surprise ambush" by Immigration and Customs Enforcement officers who had revoked her visa without notice.

Mornyang remains in custody despite ICE deeming her "an expedited removal".

"Adau Mornyang is an illegally present Australian citizen who was processed as an expedited removal," ICE public affairs officer Rachael Yong Yow told AAP on Monday.

"She was convicted July 15 of an assault stemming from a mid-air disturbance onboard an aircraft.

"Mornyang was taken into ICE custody September 17 and is pending removal from the United States."

Maria Mornyang went public with her sister's plight last week by setting up a GoFundMe page to raise $28,000 for legal fees.

By late Monday the model had only received $1030 in donations.

Mornyang made world headlines after she was arrested for slapping a flight attendant and other unruly behaviour on the January 21 United Airlines flight.

She faced a maximum 21-year prison sentence.

Prosecutors described how Mornyang ordered several glasses of wine on the flight, but was cut off when her behaviour deteriorated.

She slapped a flight attendant, struck other passengers as she walked down the plane's aisles, yelled vile racial taunts at a black air marshal who tried to restrain her and called another flight attendant "dumb white trash".

Audio recordings of her ranting were played to jurors.

Judge Cormac Carney described it as "a nightmare flight" but opted against a prison sentence after considering her troubled life as a child refugee from Sudan and being the victim of sexual assault aged 17 in Adelaide.

She was sentenced to 100 hours of community service and three years' probation.

Mornyang, a former Miss World Australia finalist who has worked with elite designers including Alexander Wang, was also ordered to undergo drug tests, substance abuse counselling and to abstain from alcohol.

Mornyang walked out of Judge Carney's court and with a visa not set to expire until December 2021 believed she could remain in the US.

"Adau was shocked since she knew she never entered the United States illegally nor overstayed her visa," Maria Mornyang wrote on the GoFundMe Page.