Kris Jenner’s sister Karen Houghton's cause of death has been revealed.

Less than a month later after her death, on Friday 12 April, Houghton’s death certificate was released and a copy obtained by TMZ.

The death certificate reveals the official cause of death as “cardiac arrest and sudden cardiac arrhythmia”.

The certificate also notes type 2 diabetes as a second underlying cause.

The documents also state that Houghton had bipolar disorder and was cremated after her death.

Houghton – the younger sister of the reality star – died on March 18 at the age of 65. At the time, it was reported that she had died of natural causes.

Jenner broke the news of her sister’s death on Instagram, in an emotional post.

“It is with the heaviest heart and deepest sadness that I share that my sister Karen passed away yesterday unexpectedly,” she shared.

“My heart aches for my mom MJ and my niece Natalie and I pray that God guides us all through this difficult time. Karen was beautiful inside and out. She was the sweetest, kindest, the most sensitive and vulnerable and so so funny...She holds such a huge part of my heart and I cherish every single memory we have together. I love you my beautiful sister.”

Houghton largely stayed out of the Kardashian-Jenner reality TV spotlight, opting for a more private life.

Publicly, Jenner and her sister hadn’t always seemed to have a close relationship.

Back in 2014, Houghton alleged in an interview that her celebrity sister had changed as a person after becoming famous.