(all Bible citations are from KJV)
[Leviticus, chapter 11]
Whatsoever parteth the hoof, and is clovenfooted, and cheweth the cud, among the beasts, that shall ye eat. Nevertheless these shall ye not eat of them that chew the cud, or of them that divide the hoof: as the camel, because he cheweth the cud, but divideth not the hoof; he is unclean unto you. (...) And the swine, though he divide the hoof, and be clovenfooted, yet he cheweth not the cud; he is unclean to you.
Then we are dozen hundreds later and there is:
[Matthew, chapter 8]
And when [Jesus] was come to the other side into the country of the Gergesenes, there met him two possessed with devils, coming out of the tombs, exceeding fierce, so that no man might pass by that way. And, behold, they cried out, saying, What have we to do with thee, Jesus, thou Son of God? art thou come hither to torment us before the time? And there was a good way off from them an herd of many swine feeding. So the devils besought him, saying, If thou cast us out, suffer us to go away into the herd of swine. And he said unto them, Go. And when they were come out, they went into the herd of swine: and, behold, the whole herd of swine ran violently down a steep place into the sea, and perished in the waters.
The Wikipedia article of Gergesenes says the city lies "to the east of the Sea of Galilee" and inhabited by people who "were culturally more Greek than Semitic" and "this would account for the pigs in the biblical account".
As this article is marked (since 2009) as lacking of sources and requiring improvement, what could be a reason to breed pigs in Israel? Or it really was not Israeli city? (sources are welcome).