Simone Biles

The Yurchenko double pike is the most difficult jump in the women's scoring code and was rated at 6.4 points by the technical committee in anticipation of it being performed.

It was named after Natalia Yurchenko as she pioneered the approach to the vault not the what Biles performed after pressing off it.

The 26-year-old athlete scored 15.266 with a 58.865 total in the all-around, securing the vault to be named Biles II after a different original jump was named after her in 2018.

Former teammates Aly Raisman and McKayla Maroney also appeared before the committee, along with FBI Director Christopher Wray.

The committee is examining shortcomings in the FBI's investigation into Nassar, later convicted of sexually abusing girls.

He is serving a life sentence in jail.

"I blame Larry Nasser, and I also blame an entire system that enabled and perpetrated [sic] his abuse," said Ms Biles, the most decorated Olympic gymnast of all-time.

"If you allow a predator to harm children, the consequences will be swift and severe," she added.

The superstar endured a difficult time at the Tokyo Games, withdrawing from the team final last week citing mental health concerns.

The four-time Olympic champion didn’t contest the all-around, floor and uneven bars events but returned to win individual bronze on the balance beam.

That medal saw her match Shannon Miller as the most decorated Olympic gymnast in US history - and there may be more to come.

Biles told NBC’s Today show on Thursday (NZT) that she was keeping “the door open” for a return to the Olympics.

The American, 24, has not competed since last week's team final, where she performed on vault but no other apparatus before saying she wanted to protect her mental health.

The pre-Games favourite, a four-time Olympic champion, has been suffering with the 'twisties', which gymnasts describe as a kind of mental block.

Biles won bronze on the beam at Rio 2016.

The American had arrived in Tokyo with a chance of six gold medals, and such has been her dominance of her sport that they were all realistic.

The 18-year-old Olympic debutant, who helped the USA win team silver on Tuesday, finished on 57.433.

Brazil's Rebeca Andrade won silver and Russian Angelina Melnikova bronze.

Jessica Gadirova's 10th place was the best result ever by a British woman in the event.

Andrade's score of 57.298 secured Brazil's first ever women's gymnastics medal at the Games, while Melnikova took bronze with 57.199.

"It's my first world ranking, so I know where I am and where I stand," said 16-year-old Gadirova, whose twin sister Jennifer finished 13th.

The American left the arena after the vault, but later returned to support her team-mates as they claimed silver behind the Russian Olympic Committee.

Biles, 24, scored 13.766 - her lowest Olympic vault score - before withdrawing from the event.

"After the performance I did, I just didn't want to go on," she said.

"I have to focus on my mental health. I just think mental health is more prevalent in sports right now.

"We have to protect our minds and our bodies and not just go out and do what the world wants us to do.

Winning her 24th and 25th world championship medals in beam and floor overnight put the United States gymnast top of the all-time medal charts for the championships.

Biles won five gold medals this week. If she can repeat that at next year's Olympics it would be a feat no female gymnast has managed at a single Games.

But for Biles, it's not about the statistics.

"I can't be more thrilled with the performance that I put out at this world championships," she said. The medal record? "I'm not a number person."

Biles, a star member of the USA's successful gymnastics team at the 2016 Rio Olympic Games, on Monday became the latest athlete to state that she was molested by Nassar.

Nassar was last month sentenced to 60 years in a federal prison for having child sex abuse images on his computer.

He is also awaiting sentencing after pleading guilty to seven counts of criminal sexual conduct in November.

Athletes affected include tennis players Venus and Serena Williams and teenage gymnast Simone Biles.

A group calling itself "Fancy Bears" claimed responsibility for the hack of a Wada database.

After the leak, Ms Biles said she had long been taking medicine for Attention Deficit Hyperactivity Disorder.

The hacker group had accused her of taking an "illicit psycho-stimulant", but she said she had "always followed the rules".

Biles, 19, won four gold medals in Rio, five in total, as a member of the Games' best gymnastics team.

"It's an incredible honor to be selected as the flag bearer by my Team USA teammates," Biles said in a statement.

Sunday will mark the second time a gymnast has carried the Stars and Stripes into an opening or closing ceremony. The first was Alfred Jochim in 1936. A silver medalist in 1932, he carried the banner into the opening ceremony at Berlin.