New Delhi, June 25 : The Central Bureau of Investigation (CBI) on Wednesday summoned Dr. Rajesh Talwar's wife, Dr. Nupur Talwar and his brother, Dinesh Talwar for interrogation in connection with the Aarushi-Hemraj murder case.
The agency has carried out several tests on the suspects. These include a narco-analysis and three lie-detector tests on Rajesh Talwar's compounder Krishna, two polygraph tests on Rajesh Talwar and one on Nupur Talwar.
On June 23, CBI was granted additional four days custody of Krishna in the case.
The agency arrested Krishna on June 13, while stating he had confessed to his involvement in the murder of Aarushi and the Talwar family's domestic help Hemraj.
On Friday, the agency had questioned Noida police over the missing evidence in the twin murder case.
"We are trying to ascertain what apparel Krishna had worn when he was picked up. So we have questioned the Noida police," CBI Joint Director, Arun Kumar, had said.
It indicates, CBI suspects the Noida police may have consciously or unconsciously tampered with the crucial evidence.
The agency may send Krishna's clothes for forensic analysis. His khukri - believed to be the murder weapon - has already been sent to a forensic lab.
Dr. Talwar, has already been under arrest since May 23 after Noida police claimed that he had murdered Aarushi and Hemraj.
Aarushi, was found murdered in her sector-25 Jal Vayu Vihar apartment in Noida on May 16.
Before the CBI took over the case, the Noida police initially named her family's domestic help Hemraj as the prime accused but backtracked when his body was found on the roof of the building the next day.
The CBI has questioned a number of people but is nowhere near zeroing in the motive for the crime.
The agency has also interrogated Talwar's family friends Durranis, domestic help Rajkumar and Talwar's other domestic help Bharti.