Aran Handa took the drastic action at the Meridian Hotel on Lang Stracht after years of frustration at trying to evict Destiny House Church members.
Mr. Handa explained he had reached the end of his tether and felt he had no other way of preventing the group using the building.
He said: "I have had enough. The cult is being kicked out.
"Bricking the hotel up was the only way we could get rid of them."
He said members had removed most of their belongings although they'd left behind some tapes.
Mr. Handa has been trying to oust Destiny House Church for years, claiming the group owed him "a substantial amount of money."
The group's predecessor, Word of Life (International), folded three years ago with £160,000 debts.
Mr. Handa alleged the group had not paid rent since putting down a deposit to buy the building in 1995.
Mr. Handa said: "We are looking for monies owed by these people.
"We will try to collect this cash but chances do not look good.
"My view is they will try to disappear and I believe they are already looking for new premises."
Mr. Handa, who is based in Newcastle, intends refurbishing the building and restoring it as a hotel.
Destiny Church leader Jim Addison refused to comment on the premises being bricked up.