Procedure to tender recorded conversation as evidence

The recorded conversation over phone cannot be relied upon as a strong evidence to defend the case despite the certificate by the transcripttion agency about its genuinity and there is no such thing called as voice samples permitted to be allowed before court as an evidence.  This may corroborate the evidence of the defence and may support the stand taken in defence.  Hence do not venture upon the ideas which will adversely affect the defence in the case.

Can a recorded conversation admissible as weak/secondary evidence without certificate by the transcripttion agency?

I agree with the view by Mr.Kalaiselvan.

There is one ruling that voice samples cannot be collected as against the will a person concerned, as it is against fundamental rights.

Further it is cell phone recorded conversation, the instrument must have been purchased by the person concerned in his name, the sim card must be in his name, the software for recording the conversation must have not been freely downloaded, the date, time and duration must match with its properties as pleaded in the defence like so on... like several questions may be put during cross examination. Original phone, sim card along with relevent bills and records must be produced.

Above all if there is any fiduciary relationship between the persons of the concerned conversation, then to use the same by one person against other is a legal wrong. Legal trust is infringed.... 

It is very week evidence....