Three men and a woman have been remanded in custody as part of an undercover police operation targeting the Belfast heroin trade.
The suspects were charged with various drugs offences following a series of raids on houses in the south and east of the city.
Appearing together in the dock were Lithuanian nationals Roman Michailov (22) and 37-year-old Gintas Vengalis.
Both men face charges of possessing heroin with intent to supply.
Vengalis, of Tavanagh Street, Belfast, is further accused of being concerned in the supply of class A drugs at various dates in January and February.
A detective told Belfast Magistrates Court he was at the higher end of the racket.
"He's got numerous aliases, fake passports and fake bank cards. This man could disappear if released," he said.
Co-accused Michailov, of Chobham Street, Belfast, is also charged with supplying heroin and acquiring criminal property, namely £100 in cash.
He is alleged to have been a "runner" caught on CCTV handing a small drugs package to an undercover police officer, the court heard.
Two others from Belfast earlier appeared in connection with the same investigation.
Ciaran Toner (34), of King Street, and Finnula Braniff (25), from College Court Central, each face multiple charges, including possession of heroin with intent to supply, acquiring criminal property and being concerned in the supply of class A drugs.
All four were refused bail and are due to appear in court again by video-link next month.