The Ranchi gang-rape puzzle remained unsolved even after 72 hours with police on Wednesday seeking forensic help to ascertain what exactly happened on a hillock not far from the capital city on Sunday evening.

SSP Prabhat Kumar, who received the report of a medical board on Tuesday night, remained tight-lipped on whether the grave allegations of two teenagers - one of them a minor - against six unidentified youths were true, but conceded that undergarments of the girls had been sent to the Forensic Science Laboratory in Hotwar.

"Since the matter is under investigation, I do not think disclosing details of the medical report will be appropriate right now. I have asked city SP Jaya Roy to discuss the findings of the medical report with doctors," Kumar said.

A vernacular daily, however, quoted the SSP as saying that the report didn't confirm rape. Kumar refused to comment on the news.

Unconfirmed sources revealed that the tests conducted by the Ranchi Sadar Hospital medical board on Tuesday on the basis of the gang rape FIR lodged at Bariatu police station on December 21 didn't confirm forceful sex. "The report suggests intercourse, but gives no indication of rape or gang rape," a source said.

It remains a puzzle why the two girls then walked into Lalpur thana, along with their two male friends, on Monday morning, claiming abduction from Circular Road and gang rape by six men on the hillock in Bariatu police station area, 5km from the heart of the city.

IG (CID) Sampat Meena, who exercises jurisdiction over all forensic probes, said they were leaving no stone unturned to crack the case.

A police source said a Christmas gathering had been organised on the hillock on the same evening that the girls were allegedly gang-raped. "We are looking for people who attended the party for more clues," he added.