A top Pakistani official has sought to doubt the authenticity of the letter written by Ajmal Amir Iman Kasab [Images], the lone gunman captured for the Mumbai terror attacks [Images], to seek legal aid from the Pakistan government.

Interior Secretary Syed Kamal Shah claimed the language and content of the letter did not "match those of a real Pakistani".

"They (Indians) have simply tried to make up a story and have even failed in that too," Shah told reporters during a visit on Tuesday to the headquarters of the National Database and Registration Authority, Pakistan's national database.

Questioning the authenticity of the letter written by Iman alias Ajmal Kasab, Shah repeated interior ministry chief Rehman Malik's contention that no records of Iman had been found in the NADRA database.

However, the database covers only 60 million of Pakistan's total population of over 160 million.

Shah also said the Indian authorities had not yet shared evidence on the Mumbai attacks with Pakistan.

"Why did the Indians not share the identity of the others accused in the attacks? They are talking just about Ajmal Kasab, who was not even arrested from the crime scene," he said.

He also said that one of the mobile phone Subscriber Identity Modules, allegedly recovered from Kasab, was issued from Austria.

Kasab's father recently admitted to the influential Dawn newspaper that the gunman whose picture was beamed round the world by the media was his son. Residents of Kasab's village of Faridkot in Punjab province too have told the Pakistani media that he belonged to the area and had told his mother during his last visit that he was going away for Jihad.