Facing criticism for illegally detaining Krishna, the compounder of dentist Rajesh Talwar, the Central Bureau of Investigation on Wednesday justified the narco-analysis on him in the Aarushi murder case saying it was done to ascertain contradictions, if any, in his statements. given to the CBI and the Noida police.

"Krishna alias Kishan has been examined to verify his statements given before Noida police. To verify contradictions appearing in his statement, he was subjected to polygraph (lie) detector test on June 9 and 10",

CBI Joint Director Arun Kumar told media-persons, reading out from a prepared statement, "To further rule out contradictions appearing in his statement, he has been sent to Forensic Science Laboratory in Bangalore for further scientific tests."

To a question whether the CBI had taken permission of a couArt before conducting the narco-analysis test, Kumar said "scientific tests are being conducted with Krishna's permission and as per provisions of law."

The FSL Bangalore had initially refused to conduct the tests sans any court order but the matter seemed to have been resolved after intervention by the highest level in the CBI.

Sources said Krishna had been detained for the last five days and was allowed to go out only for a brief period. As per law, no one can be detained for more than 24 hours without the court's permission.