An illegal Pakistani immigrant remains behind bars accused of detaining women in his car at night and assaulting them when they refused to have sex with him.

Musarat Hussein, 25, fronted a Sydney court on Sunday, crying hysterically and threatening self-harm, saying he wanted to be sent home to Pakistan.

Police told the court he was a Pakistani refugee who had had overstayed his bridging visa, which expired in August, and was currently considered an "unlawful person in Australia".

In court documents, police allege he actively went out "looking for vulnerable females late at night [whom] he could exploit for sexual gratification".

There were two such instances in the past fortnight with women detained by him in Sydney's east.

Court documents said "on both occasions the accused has used violence towards his victims to keep them inside the vehicle".

His first victim was an oncology nurse who was on her way to Prince of Wales Hospital for the night shift.

Police said she was "reluctantly" persuaded to get into his car and show him the way to Randwick when he asked for directions.

He then went the wrong way and she sent a group text to friends saying: "I'm in a stranger's car, it's a bit scary."

Hussein is accused of then asking the woman for sex, offering $200 and saying "please help me" while making masturbation gestures.

When the woman refused the man allegedly kept driving, ignoring her screams for help.

He unbuttoned his pants and she managed to unlock the door and jump out but he tried to drag her back.

Eventually witnesses heard her screaming that he was trying to "rape" her and came to her aid.

Police said the second incident happened on Saturday when he allegedly dragged a 20-year-old woman into his car at Randwick and slapped her across the face when she tried to break away.

Three passengers in a taxi that was driving past saw what was happening and stopped to help.

Hussein was refused bail with police saying he was a "flight risk", that the offences were "extremely serious" and he posed an "unacceptable risk to the community".

He will return to court on December 12.