Prosecutors claimed 39-year-old Richard David McCrea’s actions last week were part of a “disturbing pattern of behaviour”.
But defence lawyers argued that he bought the new phone to contact family on leaving prison because his old device was low on battery.
McCrea, with a hostel address at Ventry Lane in Belfast, was refused bail.
The court was told he has been assessed as a category three sex offender.
He previously portrayed himself as a 17-year-old on social media in an attempt to contact and meet a young girl, according to the prosecution.
On February 13 McCrea received an 11-month prison sentence at Antrim Crown Court for a separate breach of his Sexual Offences Prevention Order (SOPO). But because of the length of time spent in custody on remand he was released at that stage. One of the conditions was that he was not to obtain a new mobile phone without prior approval from his designated risk manager.
Crown lawyer Natalie Pinkerton claimed McCrea breached that within hours. “He immediately, on release, went to Tesco beside Antrim Courthouse and purchased an internet-enabled smartphone,” she said.
McCrea used the device to phone his risk manager the following day and confirmed what he had done, the court heard. Ms Pinkerton stressed there was no suggestion he had used the phone to commit any offence.
But she argued: “While there hasn’t been any further contact with young people, it was two hours after release from custody that he’s gone to purchase a mobile phone after being expressly told not to.”
Defence counsel said McCrea had been attempting to get to his new hostel accommodation, realised his old phone was running out of battery and bought the new device to let his family and friends know what was happening.
“It’s not a case where he was doing this to keep it secret,” he added.
The barrister also insisted his client has never committed any assault or “contact offences”.
However, Mr Justice Huddleston refused bail “given the history of this applicant and risk of further offences”,