This disclosure is considered significant because the prosecution has alleged that Faheem had drawn maps of targets and passed them on to Lashker-e-Tayiba who plotted the attacks.
Deposing before Judge M L Tahaliyani, Dr Kanti Kumar said he had matched 32 specimen signatures with the maps and found that they matched.
"This indicated that Faheem had drawn the maps," he told Special Public Prosecutor Ujjwal Nikam. The expert said he had used a special equipment fitted with a microscope to verify the signatures.
Another witness, police constable Chandrakant Raut said Faheem was in his custody on January 3 when an Uttar Pradesh Police officer had approached him for permission to take specimen signatures of the accused.
Raut said he allowed the police officer to take Faheem's specimen signatures after obtaining permission from a magistrate in Mumbai. Faheem is facing the trial with Sabauddin Ahmed and Pakistani gunman Ajmal Kasab. They are charged with the murder of 183 people.