The Central Bureau of Investigation (CBI) has requested a special CBI court in Muzaffarpur to make former RJD MP Mohammad Shahabuddin to undergo polygraph, narco analysis and brain-mapping tests in connection with the murder of Hindi daily Hindustan's Siwan bureau chief Rajdev Ranjan.

Investigating officials told the CBI court led by Anamika Kumari that Shahabuddin, who was taken on eight-day police remand, was not cooperating with the investigators. "These scientific tests are required to elicit certain information, which Shahabuddin doesn't want to share with the sleuths," an investigating officer told the court on Friday.

Shahabuddin's defence lawyer Dilip Kumar, however, denied the CBI's allegations and said Shahabuddin had cooperated with the sleuths, replying to questions posed before him. Shahabuddin appeared at the trial through video conferencing from Tihar jail. He told the court the investigating agency was hell-bent on implicating him in the case. "I have provided all relevant information to the investigators," he told the court, opposing the CBI's request.

The RJD leader requested the court to put on record the information he had shared with the investigating officials during questioning. The court has listed the case for hearing on June 15.

The court directed all the accused to be present in court on June 15 when the case will be heard. Two accused - Mohammad Kaif and Javed - are currently on bail while Laddan Miyan and his four associates are still lodged in jail.

Earlier, Shahabuddin had refused to undergo a lie-detector test, for which the CBI had submitted a petition. The CBI has already submitted a chargesheet against an accused, Sonu Kumar Soni, in the case.

Ranjan was shot dead on May 13 last year while returning from his office on his motorbike. His wife Asha Ranjan lodged a case against unknown persons with the Siwan police station. Later, she accused Shahabuddin of hatching a conspiracy from behind bars to get her husband eliminated.

Shahabuddin was lodged in Siwan district jail when Ranjan was killed. Initially, his former aide Laddan Miyan's name had figured in the case.

Chief minister Nitish Kumar ordered for the probe to be handed over to the CBI on a request from Ranjan's family. Siwan police had arrested six persons and chargesheeted them when CBI took over the investigation in the case.