"I never gave two contradictory and conclusive reports and the notice for my prosecution for the offence of perjury was not maintainable as I was an expert witness and did not deviate from my report," the counsel for ballistic expert Prem Sagar Minocha told a bench comprising Justices S Ravindra Bhat and G P Mittal said.

Minocha is among 31 prosecution witnesses who were issued perjury notices by the High Court for allegedly taking a somersault during the trial of Jessica murder case which led to the acquittal of Siddharth Vashist alias Manu Sharma and eight others by the lower court.

The High Court then reversed the verdict which was later upheld by the apex court.

During the hearing, Delhi Police opposed the plea of Minocha that he being an expert witness cannot be tried for the offence of perjury.

It was Minocha, who during his cross-examination, introduced the two-weapon theory, which was contrary to the report, and helped the accused, police had claimed.

"For the commission of offence of perjury, a witness has to retract from his earlier statement and here, he appeared to assist the court for the corroboration purposes," the defence counsel said.

The report, which was based on the scientific analysis, was inconclusive, Minocha said. Besides Minocha, eight other witnesses, who are facing perjury notice, also advanced their arguments.

The bench has now the fixed the matter for April 21 for hearing rebuttal arguments on behalf of Delhi police.

Earlier, it had questioned the prosecution of all the witnesses, who took somersault during the trial, saying the incident of "turning hostile" has become an "endemic" and all such persons cannot be painted with same brush.

"How the case of prosecution will move? The incidents of witnesses turning hostile and doctored evidence have become an endemic now. Some fears for his life, some gets tempted and some does not support (the prosecution) for obvious reasons. Should we go ahead and prosecute all of them?," it had asked.

The case dates back to April 1999 when Lall was shot dead by Manu Sharma after she refused to serve drink to him at a late night party at socialite Bina Ramani's restaurant Tamarind Court here in South Delhi.

The High Court, which reversed trial court's verdict on December 18, 2006 and awarded life imprisonment to Manu Sharma, later issued notices to the witnesses, asking as to why they should not be prosecuted for the offence of perjury.

Later, ten witnesses were absolved of the charges.

Earlier, Bollywood actor Shyan Munshi, who had lodged the FIR, pleaded the court not to prosecute him saying "he cannot be termed hostile as even the apex court had used part of his deposition in convicting the accused."

Munshi, the complainant in the case, disowned the complaint, saying he did not know Hindi.

The prosecutor pleaded before the court to refer to 19 out of the 31 hostile witnesses, including Munshi, to the magisterial court for their trial on charges of perjury.

The prosecutor had pointed out that out of total 31 witnesses, now only 19 were available for trial as three are dead while the court itself had discharged 10 of them earlier on the ground that there was no major deviation between their statements to the police and later to the court.

The 19 persons, who were facing court proceeding for turning hostile in the case included socialite Andleeb Sehgal, ballistic experts Roop Singh and Prem Sagar, electrician Shiv Shankar Dass and eyewitness Jagannath Jha.

The apex court, while upholding the high court's ruling in Jessica Lall murder case last April, also endorsed its findings on the issue of perjury.