The sister of Nima Momeni — accused of fatally knifing Cash App founder Bob Lee — attended court to support her sibling as he pleaded not guilty to the murder Thursday.

Khazar “Tina” Elyassnia, who is alleged to have taken drugs and attended sex parties with Lee, appeared wearing all-black attire and sunglasses alongside her mother but notably without her plastic surgeon husband, Dino.

Momeni finally entered his plea through his attorney at San Francisco Superior Court after previous arraignments had been delayed, the San Francisco Chronicle reported.

Also in court for the hearing was Bob Lee’s ex-wife, Krista, who has defended him amidst claims about the lurid sex and drug-fuelled lifestyle he was said to be living at the time of his death.

Momeni’s attorney, Paula Canny, had argued he should be released on bail because he was not identifiable in grainy camera footage the police say showed him standing with Lee minutes before he was stabbed.

Canny told The Post videos provided by prosecutors only showed “indecipherable blurs.”

But the judge disagreed and ordered Momeni, 38, shall remain in San Francisco County jail.

Canny also argued in a recent bail motion that her client never fled the scene and noted Lee never mentioned him in a frantic 911 call.

“If a person wants to kill another person, why would the assailant allow the person they are trying to kill to walk away. They would not,” Canny wrote.

“They would stab them in the back. They would not let them walk away.”

She added when her client last saw Lee, the 43-year-old tech whiz “was walking upright,” according to the motion.

Prosecutors have alleged Momeni’s sister is at the center of the fatal feud between Lee and Momeni.

Hours before the stabbing, Momeni was said to have confronted Lee about his sister’s alleged drug use and “inappropriate” behavior after Lee spent the day with her and others, cops said.

Investigators said they learned Lee and Elyassnia had known each other for years. Lee was found to have ketamine and cocaine in his body in an autopsy.

Lee allegedly assured Momeni nothing “inappropriate” had happened before he continued his night.

Hours later, Lee left his friend, and was seen entering Elyassnia’s apartment around 12:39 a.m.

Surveillance footage also shows Lee and Momeni riding an elevator down to the lobby of Elyassnia’s apartment building shortly after 2 a.m. and climbing into Momeni’s white BMW, the document states.

Video then shows the pair inside the BMW as it arrives at a “dark and secluded area” on Main Street, near where a bloodied Lee was later found.

Prosecutors allege that the men both left the car and Momeni stabbed Lee.

Lee was “violently bleeding” when he called 911 shortly after he was stabbed on April 4, when a dispatcher said there was “a male screaming ‘help,’ saying ‘someone stabbed me’ … Advised he is bleeding out.

Momeni, a tech consultant, was arrested more than a week later.

The Wall Street Journal reported Lee and Elyassnia were known to frequent underground drug and sex parties.

Canny told The Post her investigation so far “shows there was never a romantic relationship between Bob Lee and Nima’s sister.”

Both sides will be back in court Friday for a brief hearing regarding scheduling. Momeni is not required to attend.