More than 100 people have been warned about their safety after the police seized documents linked to the paramilitary UVF, a court has heard.
Mr Hill appeared at Belfast Magistrates Court
The details emerged during a bail hearing at the High Court in Belfast.
Darren Richardson, 30, of Moneynick Road, Randalstown, County Antrim, is charged with UVF membership.
He faces a further charge of possessing documents that could be useful to terrorists and having 30 rounds of ammunition. Bail was refused.
Names, addresses and car registration numbers were in five hand-written documents found during a police search in Ballymena, County Antrim, last week, the court heard.
A Crown lawyer said the police search was at the premises of Wright Bus, where Mr Richardson is a manager.
The ammunition was found in his desk and the documents elsewhere in his office, the court heard.
The documents contained 104 vehicle registration numbers, as well as the names and addresses of 51 people.
'Records of vehicles'
Another document found in Mr Richardson's car contained 13 registration numbers and personal details, the lawyer said.
The defendant told police he had made records of vehicles acting suspiciously near his home and kept the lists to establish if anyone on them were republicans, the hearing was told.
He also said he had been given documents by a man he refused to name and had also received information from a serving soldier in the Royal Irish Regiment, whose name he gave to police.
The lawyer said police believed the unnamed man was Aaron Hill, who worked in the PSNI Crime Management Unit, and who appeared in court on Monday.
"As a result of all this, police have had to warn 117 individuals about their safety," said the lawyer.
"Police are trying to establish the identity of others who may be a risk by checking a computer used by (Mr) Hill to see what additional information that throws up."
A defence lawyer said Mr Richardson had been "extremely misguided".
"What seems to have happened is that he started down a road several years ago in a sort of glorified neighbourhood watch and then, by association with these two persons, this activity spiralled out of control."
He said the defendant denied membership of the UVF and had never been involved in acts of violence.
The court was told the RIR soldier had been interviewed, but to date he had not been charged.