An investigation into suspected human trafficking uncovered a huge computer hacking operation at a Belfast apartment, the High Court heard.
Police found a laptop containing bank details for multiple individuals and set up to print counterfeit Spanish La Liga football tickets, prosecutors said.
Details emerged as bail was refused to a Romanian man arrested in the raid at Alfred Street in the city on June 28 last year.
Daniel Marincu (32), of no fixed address, faces charges of possessing articles for use in fraud and fraud by false representation.
He was detained after an intelligence-led search to identify victims of people trafficking, a judge was told.
Two women in the flat with him confirmed they were escorts, but denied knowing the accused.
He is not accused of any exploitation or trafficking offences.
Crown lawyer Fiona O'Kane claimed that a laptop used by him contained a programme that could access other computers.
Photos on screen showed statements for an individual in the same apartment complex.
Another window showed an attempt to get into a Government pensions website, it was alleged.
Investigations launched by cyber-crime officers revealed multiple identity cards for various foreign nationals stored on the device, the court heard.
Names, addresses, dates of birth, phone and credit card numbers, passwords and log-in details were all detected.
"It was a massive amount of data, one terabyte in well-structured directory folders," Mrs O'Kane said. "There were also images and files to enable printing of suspected counterfeit La Liga football tickets."
Marincu admitted buying the laptop in London but declined to say who from. The court heard he said he used it for Facebook.
The accused was seeking bail to live at an address in Co Tyrone.
Despite a Romanian associate offering a £5,000 cash surety, Mrs O'Kane claimed he could use connections in Spain, England and his native country to flee.
Marincu claims any hacking was carried out by others at the address accessing the laptop.
Denying bail, Mr Justice Deeny said: "There's a strong prima facie case against him, given the amount of information, of serious offences of fraud."