Unnao rape survivor is on the ventilator after the car crash on Sunday (File)

The CBI has assigned 20 more officers to conclude the probe into the car crash of the Unnao rape survivor, who is battling for life in a hospital since Sunday. The addition of these officers has taken the number of personnel in the investigating team to 25. The move comes a day after the Supreme Court ordered the agency to complete the probe within a week.

"CBI has constituted an additional Special Team of around 20 officers including SP, ASP, DSP, Inspector and SI level officers to assist in the case registered on July 30 related to Unnao survivor accident case," the agency said in a statement.

"Apart from this, a six member CFSL (forensic) team of CBI have left for the accident spot for examination. Investigation in the matter will continue as per Supreme Court order." it added.

The teenager is on the ventilator after the car crash on Sunday, when the Swift Dzire she was travelling in was hit by a truck in Uttar Pradesh's Rae Bareli. Two of her relatives died in the crash, and her lawyer is also critical after sustaining injuries.

A First Information Report (FIR) lodged a day after the car crash named Kuldeep Sengar-- who she accused of rape in 2017-- his brother Manoj Singh Sengar and eight others. The case was subsequently transferred to the CBI.

A bench headed by Chief Justice Ranjan Gogoi said the CBI's probe into the car crash must be completed in seven days and the trial in all five cases, including the rape case, must end within 45 days. More time could be given for the crash investigation if required, the court added.

A five-member CBI team is currently in Rae Bareli, trying to recreate the accident. It has also sought details of the politician's visitors in jail.

Sources say CBI officials have recorded the statement of police officers who arrived first at the site of the crash.