Bruce Jenner and NBA player Lamar Odom
Lamar Odom knew Bruce Jenner is dating Kris Jenner's friend Ronda Kamihira. Getty

Khloe Kardashian's estranged husband Lamar Odom reportedly knew about the relationship between her father-in-law, Bruce Jenner, and her mother's best friend Ronda Kamihira.

According to Hollywood Life, Odom, a 34-year-old professional basketball player, is supportive of 64-year-old Jenner's decision to start dating again, even though he is still technically married to wife Kris.

Kamihira was best friends for 20 years with Kris Jenner, who filed for divorce last month. She has two daughters, Maddy and Spencer, who are friends with Bruce and Kim's daughters Kendall and Kylie Jenner.

"Lamar's known about Bruce's relationship for a while now," a source told the website. "He and Bruce talk about everything under the sun. They don't lie or sugarcoat anything."

Odom has remained close to Bruce Jenner even after Kardashian filed for divorce last year, citing irreconcilable differences.

Odom's marriage to the Keeping Up With the Kardashians star first hit the rocks when a video surfaced showing him rapping about how he cheated on her. He was also allegedly not willing to take professional help for his drug addiction.

"Bruce was one of the only people who stood by Lamar and supported him when he was at his worst," the insider added. "Bruce was like a father and a mentor to him during that time and even now."

Kris Jenner, meanwhile, filed for divorce from Bruce on 22 September, 11 months after they announced their split. Star magazine claimed they split because of his sexuality.

However, Kris spoke out about the rumours surrounding her estranged husband, telling Entertainment Tonight: "Ninety-nine percent of the stuff in the tabloids is made up."