There was no immediate evidence that Ebola caused his death, but panic broke out in Oyi when locals learned that he had died in Liberia, one of three countries ravaged by the deadliest known outbreak of the virus, an Anambra government spokesman Emeka Ozumba, told AFP.
"The government decided to keep the corpse away from relations and the public until we are sure of the cause of death since the body was flown in from Liberia," Ozumba said.
The length of the man's stay in Liberia or the precise day he died were not immediately known.
"The step is precautionary," Ozumba said, adding that tests would be run on the body before it would be released.
Scores of people are thought to have contracted Ebola while burying relatives who died of the virus.
Liberian President Ellen Johnson Sirleaf has said the outbreak in her country, where 156 people have died, was "nearing a catastrophe."
The only confirmed Ebola death in Nigeria was that of Liberian government official Patrick Sawyer, who contracted the virus from his sister before travelling to Lagos on July 20.
He was visibly sick upon arrival at the airport, placed under quarantine and died on July 25.
Global concern has soared in recent days over the outbreak which has infected more than 1,300 people and killed 729 since the start of the year, in Guinea, Liberia and Sierra Leone, with one death recorded in Nigeria.