The trial began in the additional chief judicial magistrate's court for the Scheduled Tribes and the Scheduled Castes cases.
The Central Bureau of Investigation (CBI) in its charge sheet filed in the court earlier said three men - Shahabuddin, Sohan lal and Baldev Jat alias Balia - kidnapped Bhanwari from Bilara in Jodhpur rural area on Sep 1 at the alleged behest of Maderna and Malkhan, killed her and then handed over her body to a gang of criminals headed by Bishnaram.
The gang burnt the body to ashes and dumped her remains in a canal.
The CBI also claimed in the charge sheet that Bhanwari was blackmailing Maderna and Malkhan, the two most powerful politicians in the region, on the basis of a CD showing both in a compromising position with her.
In the opening statement Monday, the prosecution gave a detailed account of Bhanwari's life after she became a government auxiliary nurse and midwife. The CBI counsel also narrated the circumstances which drew the nurse close first to Malkhan and then Maderna.
A panel of lawyers appointed by the CBI, including Azaz Khan, Shyam Singh Yadav and Ashok Joshi, made the opening statement.
The three lawyers told the court how the sex CDs were prepared by the nurse.
"Bhanwari was blackmailing Maderna and Malkhan on the basis of the CDs which led to her abduction Sep 1," the lawyers told the court.
After hearing the opening statement from the prosecution, the court has fixed May 21 as the next date of hearing.
The CBI had on Feb 29 filed a supplementary charge sheet in the case, naming Maderna as the mastermind behind the nurse's disappearance and subsequent murder.
The charge sheet contained accounts of 300 witnesses and 313 documents in evidence.
According to the charge sheet, Malkhan Singh had not been given a ministerial birth in the cabinet in 2008 when the Congress came to power and that is why the CD was prepared, which became the foundation of Bhanwari's kidnapping and murder.
The CBI has charge sheeted Maderna, Malkhan Singh, Indra Bishnoi and Malkhan Singh's brother Parasram Bishnoi as the key conspirators while 11 others -- including Sohan Lal, Shahabuddin and Baldev Jat alias Balia, Umesha Ram, Sahi Ram Bishnoi, Bishna Ram Bishnoi, Om Prakash Bishnoi, Kailash Jakhar and Ashok Bishnoi -- have been named the murderers.
Bhanwari's husband Amarchand has also been booked for criminal conspiracy. Indra Bishnoi is still on the run.
Most of the accused have been booked under the Indian Penal Code (IPC) sections for murder, kidnap, criminal conspiracy and causing disappearance of evidence.