Rob Kardashian allegedly knew about Lamar Odom's drug addiction "for over a year".
The younger brother of Lamar's wife Khloé Kardashian reportedly lived with the basketball star while he was using substances.
Lamar is said to be battling an addiction to OxyContin and Ambien.
Although Rob previously kept quiet about Lamar's drug use, he is now said to be focused on supporting his sister.
“Rob's known about Lamar’s drug addiction for over a year. How could he not as he has lived under the same roof with Lamar and Khloé? Rob even spent a significant amount of time with Khloé and Lamar when he was traded to the Dallas Mavericks,” a family insider told RadarOnline.
“Rob isn’t a party animal like Lamar, and drugs just aren’t his scene. The two used to be very close, but have drifted apart because Lamar has been abusing Oxy and cheating on Khloé. Rob has continued to live at the Tarzana mansion to support Khloé, he really has her back.”
The 33-year-old sportsman has been the subject of numerous scandals recently. It has been alleged he is hooked on crack cocaine, and that he spent time in rehab last August after coming under pressure from the Kardashian family.
"[Lamar] is really trying to make amends with both Khloé and Rob,” the insider added. “Khloé is being more receptive, but Rob is very suspicious because Lamar is still refusing to go to rehab.”
There has also been speculation that Lamar has been unfaithful during his marriage to Khloé.© Cover Media