The man, who was charged under the name Razan Nocolae Gros, 25, was charged with controlling Romanian women for the purposes of prostitution.
However Derry Magistrates Court heard how his fingerprints also matched fingerprints taken by Gardai in Donegal which belonged to a man known as Christian Toplicean.
Gardai had previously issued a bench warrant for Toplicean’s arrest on September 15th last.
An officer in the PSNI’s organised crime branch told Judge Barney McElholm that the defendant’s flat was searched on Monday.
The defendant and a Romanian woman whom the defendant said was his girlfriend were inside the property.
The officer said “paraphernalia associated with prostitution” had been found.
He said the defendant told the police he had been living there for about three months.
The police witness said officers seized eight mobile phones, a sum of money and 12 sim cards for use in Northern Ireland and the Republic of Ireland.
Several of the sim cards were marked with female names, which police believe to be the names of prostitutes operating on both sides of the border between Donegal and Derry.
The officer said that during the interview, the defendant denied that the Romanian woman in his flat was a prostitute and that the flat was being used for the purposes of prostitution.
However, he said that several friends would visit the flat for 10 to 15 minutes.
The officer said one of the mobile phones was examined by a forensic officer who found links which he believed related to six prostitutes who advertised online.
The officer said the defendant’s fingerprints were taken and shared with Gardai.
Mr Gros was remanded in custody.