Kris Jenner's younger sister claims she witnessed Lamar Odom's ''eyes rolling back'' into his head during a family Thanksgiving dinner.

Karen Houghton alleges she saw the basketball player - who is married to Kris' daughter Khloe Kardashian - in an incoherent state last November and believes it could support reports he has a problem with crack cocaine and some prescription drugs.

She told the new issue of In Touch weekly magazine: ''At Thanksgiving [dinner], I saw Lamar's eyes rolling back. He and Khloe stayed for 45 minutes and left - on Thanksgiving! That was weird. We all kind of looked at each other.''

Karen believes Khloe is under stress from trying to keep her four year-marriage together but she is confident her niece will survive the situation.

She said: ''Khloe's been going through hell. She's vulnerable and keeps everything inside, but she's one of the strongest girls I know. I see her coming out of this.''

The sensational claims come in the wake of Lamar's short spell in an unknown rehab facility last month.

Reports by TMZ claim Lamar has been clean for five days and thinks he can use a ''self healing'' technique to maintain his sobriety without the need to check into a clinic as he is hoping to overcome his problems through his own willpower because he has done it successfully before.

It's believed he is cutting out certain ''friends'' who he thinks may be a bad influence to make sure he does not relapse.