Rapper Kanye West's bitter feud with rapper Jay Z reportedly stemmed from his "frustration" that his wife Kim Kardashian is not close friends with Jay Z's wife Beyonce Knowles.

According to a source, West was "forcing" his wife to be friends with Jay Z and Beyonce so they could have a better relationship, but Beyonce had little in common with her, reports pagesix.com.

This comes amid claims that West's furious rant onstage nine months ago caused the fall-out with Jay Z.

"(Kanye's) rant was really about Kim and Beyonce not being best friends. Kanye is frustrated that his wife does not have a better relationship with Beyonce," the source said.

The source added that West wanted to put "pressure" on Jay Z to get their wives to be friends.

"Beyonce is a Southern, God-fearing woman, despite what you may see when she's entertaining. She may not have much in common with Kim," the source added.