In a move likely to inflame an already tense relationship with Pakistan, the Indian government has revealed publicly for the first time a dossier of evidence presented to Islamabad linking the leader of the Pakistan-based Lashkar-e-Taiba, the group blamed for the Mumbai attacks.
The co-ordinated attacks by armed men on several locations across India's financial capital last November left at least 170 people dead and hundreds wounded.
The attacks have strained relations between New Delhi and Islamabad.
Now, in an exclusive interview with Al Jazeera's Hamish Macdonald, P Chidambaram, India's interior minister, says Pakistan is "deliberately" stifling the investigation by failing to follow up on the evidence.
Chidambaram produced documents detailing names, times and locations of alleged meetings involving Hafiz Saeed, the Lashkar-e-Taiba chief, and those who went on to conduct the attacks.
Pakistan has repeatedly refused to re-arrest Saeed because it says India has failed to produce convincing evidence.
Beyond that, the dossier chronicles India's efforts in recent years to persuade Pakistan to investigate suspects involved in attacks in India and to close down "terrorist training camps" inside Pakistani territory.
In the final pages, India demands that Pakistan hand over "conspirators" to face trial in India and comply with its promise to stop armed groups from functioning inside its territory.
"There is enough evidence to show that, given the sophistication and military precision of the attack, it must have had the support of some official agencies in Pakistan," Manmohan Singh, the Indian prime minister, said on Tuesday.
But Pakistan rejected the allegation.
"Scoring points like this will only move us further away from focusing on the very real and present danger of regional and global terrorism," Sherry Rehman, Pakistan's information minister, said in a statement to the Reuters news agency.
"It is our firm resolve to ensure that nonstate actors do not use Pakistani soil to launch terrorist attacks anywhere in the world."
Pakistan has said it is examining the information sent by India. Also, a Pakistani court on Saturday resumed hearing a case against the alleged masterminds of the Mumbai attacks.
Proceedings were initially launched against five men, but two more suspects have since been arrested, according to a state-run news agency report last week.
The five suspects arrested earlier and being tried are Zaki-ur-Rehman Lakhvi, a Lashkar commander, and four others - Hammad Amin, Abdul Wajid alias Zarar Shah, Mazhar Iqbal alias Abu Qama and Shahid Jameel Riaz.
The two more recently arrested men are Jameel Ahmed and Younus Anjum.