50 Cent has slammed Kanye West's choice in dating Kim Kardashian.

The rapper - whose real name is Curtis Jackson - has always been a musical rival of Kanye's but now he may have ignited a bigger feud after suggesting his girlfriend is "trash".

Referring to Kanye's new song 'Perfect Bitch', which he said is about Kim, 50 Cent reminded readers that the reality TV star is only perfect in her partner's eyes.

He told XXL magazine: "I mean ... if that man feel like she's perfect, then she's perfect. He could mean it and you'll end up singing the words to it because he's Kanye."

The rapper continued to say that what one man considers beautiful could be seen as ugly by another.

He added: "You know how it is? One man's trash is another man's treasure."

The artist - who used to date talk show host Chelsea Handler - then said he didn't know if there was such a thing as a perfect woman.

He continued: "I'm not sure. The smartest guys I know have lost being a bad judge of character in that area."