New Delhi, Jan 16 (Agencies): India expressed its ‘disappointment’ over Pakistan's delay in bringing the perpetrators of Mumbai terror attack to justice, saying ‘real investigation’ has not taken place in that country.

Home Secretary Gopal K Pillai said the prosecution attempt in Pakistan to bring the 26/11 guilty to justice "has not moved an inch" and India's request for providing the voice samples of the handlers of the attackers has fallen on deaf ears.

When Home Minister P Chidambaram asked for action against the 26/11 perpetrators and voice samples of handlers of the attackers during his Islamabad visit last year, his Pakistani counterpart Rehman Malik told him that "you would not be disappointed by our response".

But, Pillai said that "seven months down the line, there is no Pakistani response. We are disappointed."

On the eve of the second anniversary of the Mumbai terror attacks in November last year, India had conveyed to Pakistan that "substantive and verifiable" progress has not been made in the probe into Mumbai attacks case in that country.

Asking Islamabad to fulfill its "obligation and commitment" to bring to justice the perpetrators of the 26/11 carnage, India had regretted that no feedback has been received on several issues raised by New Delhi.

This included voice samples of Pakistan-based "handlers" of the 10 terrorists who attacked Mumbai and information about seven persons involved in the attacks whose names were given by Chidambaram during his meeting with Malik in June in Islamabad.

The names of seven "handlers" involved in terror attacks included that of two officers in the Pakistani Army.

New Delhi had also conveyed to Islamabad that it wants to send a commission to Pakistan to question jailed LeT terrorists, including Zaki-ur-Rehman Lakhvi, and to get voice samples of the masterminds who were present in the control room directing the attackers.