Pakistan may ask India for custody of the only gunman to survive the Mumbai attacks to strengthen its prosecution of those behind the assault, Pakistan's top interior ministry official said yesterday.

Islamabad acknowledged for the first time this week that the November attack in the Indian financial capital was launched from and partly planned in Pakistan.

Pakistani investigators lodged a police complaint against eight suspects, including Mohammad Ajmal Kasab, a Pakistani militant caught alive by Indian forces during the attack that killed at least 179 people between November 26 and 28.

Nine gunmen were killed in the assault.

"If investigators recommend it and the court asked for him, then definitely we will do that," Rehman Malik, adviser to the prime minister on the interior, told reporters when asked if Pakistan would seek custody of Kasab.

"It's premature but when the name of a person appears in a (police complaint), he is needed in the case... We will do it when our investigators think he is needed here."

Pakistan says six of the eight suspects, including one ringleader, are in custody and two are at large.