17 remaining USA Gymnastics board members have until Wednesday to resign

Otherwise the USOC will decertify the body, revoking its status with Olympics

Former national team doctor Larry Nassar was sentenced to 175 years in prison

He abused more than 100 female athletes including many Olympians

At least four members of the USA Gymnastics board have already resigned

The US Olympics Committee has threatened to decertify USA Gymnastics unless the entire board resigns by Wednesday.

The threat, along with a slew of other mandatory conditions to avoid decertification, came on Thursday in an email from USOC CEO Scott Blackmun to the USA Gymnastics board obtained by USA Today.

It comes amid amid increasing public pressure after disgraced long-time national team doctor Larry Nassar was sentenced to up to 175 years in prison for abusing young female gymnasts.

After condemning him to the rest of his life behind bars, Judge Rosemarie Aquilina told Nassar: 'I just signed your death warrant'.

Four of the 21 USA Gymnastics board members had already resigned by Thursday, including the chair, vice chair and treasurer.

USOC CEO Scott Blackmun (above) has demanded that the entire USA Gymnastics board resign by Wednesday on threat of immediate decertification

Larry Nassar was sentenced to up to 175 years in prison for abusing young female gymnasts. The fallout has prompted USOC to demand the entire USA Gymnastics board resign

Blackmun said in his email that he did not individually blame them for the sex abuse scandal, but insisted systemic change was needed.

'We do not base these requirements on any knowledge that any individual USAG staff or board members had a role in fostering or obscuring Nassar's actions,' Blackmun wrote.

'Our position comes from a clear sense that USAG culture needs fundamental rebuilding,' he continued.

The deadline for resignation came after a more general call for the board to resign in an open letter from Blackmun earlier in the week.

Blackmun listed a slew of demands in the email to the USA Gymnastics board

Nassar is escorted into the courtroom during his sentencing hearing. He was sentenced to 175 years

Blackmun's email laid out the other following mandatory steps for USA Gymnastics to avoid immediate decertification:

An interim board must be in place by February 28. No one currently serving on the board is eligible to be an interim member except the five athlete representatives.

USA Gymnastics then has 12 months to replace the interim directors. Current board members are not eligible for those seats, either.

Also within 12 months, USA Gymnastics must cooperate with the independent investigation into whether anyone knew about athlete complaints of Nassar's abuse and failed to report them.

The new board must 'substantively discuss' at each of its meetings how the federation is progressing in implementing 70 recommendations made by former federal prosecutor Deborah Daniels and report back regularly to USOC.

All USA Gymnastics staff and board members must complete SafeSport training offered by the US Center for Safe Sport within three months.

All staff and board members must complete a comprehensive ethics training unit within the next six months.

USA Gymnastics said in a statement posted on its website that the body 'completely embraces the requirements outlined in the (email)'.

Nassar had agreed to serve a minimum sentence of 40 years as part of a plea deal, with that prison time coming after he completes his 60-year federal sentence for child pornography charges

'We understand that the requirements imposed by the letter will help us enhance our ability to build a culture of empowerment throughout the organization, with an increased focus on athlete safety and well-being,' said USA Gymnastics.

The fallout from the Nassar case has continued to spread, with Lou Anna Simon, the president of Michigan State University where Nassar also worked, stepping down late on Wednesday night.

'As tragedies are politicized, blame is inevitable. As president, it is only natural that I am the focus of this anger,' Simon said in her resignation letter.

Michigan State University President Lou Anna Simon also resigned from her role as president at the university where Nassar also worked (Simon above in court last Wednesday)

On Thursday, Kevin Martinez, an ESPN executive, became the latest USA Gymnastics board member to resign.

'I joined the board just nine months ago, well after Nassar's departure from USAG, in the hopes of helping to move the organization in a positive direction,' Martinez said in an emailed statement to Reuters.

'That hope for this board is no longer possible so I submitted my resignation.'

The webpage listing USAG's board members had been taken down on Thursday without explanation.

Most of the remaining 17 board members contacted by Reuters either declined to comment or did not return requests for comment.