Tremayne Beattie refused to name those allegedly intimidating him after being arrested for a suspected drugs handover at a retail car park on Tuesday.
The 44-year-old, of Islandview Gardens, Greyabbey, faces charges of possessing cannabis resin with intent to supply and having criminal property.
His co-accused, 28-year-old Gerard Hughes, from Norglen Parade, Belfast, is accused of supplying cannabis and possession of amphetamines.
The city's Magistrates' Court heard both men were detained after police saw a plastic bag being passed between two cars at the Connswater shopping centre.
Twenty bars of cannabis with an estimated £25,000 street value were found after officers stopped the vehicle Beattie was in, a detective said.
She added: "He gave an account at interview and will say he was in fear and in debt to certain people. He will not tell us who these people are."
The detective claimed, however, that text messages connected to the case do not back the accused's account.
Hughes was detained after his car was stopped nearby. A quantity of white powder confirmed as amphetamines was allegedly discovered in that vehicle.
His lawyer argued there was no forensic evidence or admissions linking him to the cannabis seizure.
Both men were refused bail due to the risk of any re-offending.
District Judge Fiona Bagnall pointed out: "I am told that this is part of a bigger, more sophisticated operation."
Beattie and Hughes were each remanded in custody to appear again by video link next month.