A senior Indian government official has suggested that leading figures in the Pakistani establishment must have known of the plot to carry out last November's deadly attacks in Mumbai, and hinted that some may have actively supported it.

Shivshankar Menon, India's foreign secretary said he found it "hard to believe that something of this scale ... could occur without anybody, anywhere in the establishment knowing that this was happening."

Speaking to reporters in New Delhi, Menon dismissed repeated Pakistani assertions that the attacks were carried out by "non-state actors" and said India was unimpressed by Pakistani pledges to crackdown on suspects.

The attacks on multiple targets in India's financial capital lasted for nearly three days and left 179 people dead with hundreds more wounded.

Menon's comments came after Indian officials handed Islamabad evidence they say clearly shows the attack originated in Pakistan.

New Delhi has previously been careful not to blame the attacks on the Pakistani government, and Monday's statement accused "elements in Pakistan" of being behind the plot.

'Establishment' blamed

However, Menon later pointed a finger of blame at the country's "establishment".

India has stepped up security around Mumbai since the attacks [GALLO/GETTY]

He also called for Pakistan to extradite suspects linked to the attacks so they could be brought to "Indian justice.''

Pakistan has said any trials will take place in its own courts.

India has blamed the attacks on Lashkar-e-Taiba, a Pakistani-based group, but Islamabad has requested firm evidence showing the attacks were launched from across the border.

Indian officials said the dossier handed to Pakistan - as well as to officials from the foreign countries whose citizens were killed - will make their case, and it is now up to Pakistan to act.

Officials said the evidence handed to the Pakistani high commission on Monday included information on weapons used in the attacks, and data obtained from satellite phones.

Interrogation

The material also includes details of the interrogation of Mohammed Ajmal Amir Iman also known as Mohammed Ajmal Kasab - the lone surviving gunman from the attacks who India says is a Pakistani national.

Pakistan has arrested at least two Lashkar leaders accused of planning the attacks and launched a nationwide crackdown on a charity believed to be a front for the group.

But Menon dismissed those moves as insufficient, saying the charity was still operating while Pakistani authorities had not informed India about the status of the two men they said had been arrested.

"What we have seen so far does not impress us,'' he said.