The Indian foreign ministry says it turned over a seven-page dossier of evidence against Saeed that answers questions raised by Islamabad about previous information New Delhia supplied.
"Pakistan is asking for answers to questions which are already there," Home Minister Palaniappan Chidambaram told the news agency Dawn. "Nevertheless, I have taken the trouble of dictating the (new) response."
Chidambaram said Pakistan could arrest and prosecute Saeed with the evidence already provided.
India believes Saeed is one of the 38 people who planned the guns-and-grenades attacks on Mumbai, which includes India's financial and entertainment hub.
He was put under house arrest in December, but in June a Pakistani court said he could no longer be held because of a lack of evidence.
Saeed heads the group Jamaat-ud-Dawa, which he says provides social welfare programs to poor Pakistanis. But India says the group is a front for the terrorist organization Lashkar-e-Toiba.