The incident took place on the night of June 11 in an area under Chakiya Police Station limits.
According to the survivor, the accused entered the house around 11.30 pm when she had stepped out to use the toilet.
After she returned, the men allegedly gagged her, confined her husband and took her to a secluded spot near the house, where they raped her.
She further alleged that the attackers slashed her chest and thigh with a blade when she tried to resist and raise an alarm.
Survivor says she lost consciousness during assault
Speaking to reporters, the woman said she was initially taken to a local hospital and later referred to the district hospital for treatment.
Despite receiving medical care, she continued to suffer severe pain.
"I was treated, but I had continuous pain in my private parts. During the medical examination, doctors said the pain was because of injuries sustained during the crime. Later, when the pain did not subside, we returned to the hospital. During another examination, a bullet, a stone and a piece of wood were removed," she said.
The survivor added that she had no knowledge of the objects allegedly inserted into her body because she had lost consciousness during the assault.
Previous assault allegedly ignored
The woman also claimed that three months earlier, three men had broken into her house, assaulted her and attempted to sexually assault her before fleeing with cash and jewellery.
She alleged that although the police were informed about the incident, no action was taken at the time.
Police launch scientific investigation
Begusarai DSP Anand Kumar Pandey said a detailed investigation is underway and that preliminary findings support key aspects of the survivor's statement.
"The woman's statement appears to be true. She went home after being discharged on June 12. When she returned home, her internal parts were showing signs of damage. A bullet has been removed from the private parts," the officer said.
He said police are conducting a scientific investigation into the case and expressed confidence that the accused would be arrested soon.
The officer also assured that action would be taken against any police personnel found guilty of negligence in handling the matter.
Probe continues
Police are examining medical reports, forensic evidence and witness statements as part of the investigation.
Authorities have not yet disclosed whether any arrests have been made in connection with the alleged assault.
The case has sparked outrage locally due to the extreme nature of the allegations and renewed questions about police response to complaints of violence against women.