Fr Joseph Mulimbi Nguli, 52 and from the Katuba area, was left for dead in the attack. Police say he was shot at some point in the night between 21 and October 22.
Bishops in the country released a statement blaming bandits for the killing and expressing concern at a rise in violence against Christians.
Bishop Denis Moto, vicar General of the Archdiocese of Lubumbashi, told AFP: "Around 22:00 two armed masked men who had entered the family property where he was spending his holiday, shot him in the stomach while he was driving his vehicle onto the compound.
"They fled after."
Police said they found an AK-47 weapon when they arrived at the scene. Detectives raised the prospect the killing could be a revenge attack.
Bishops said in a statement: "We are concerned about the... resurgence of banditry."
