India - Indian security officials have begun questioning a key figure allegedly involved in the planning of the deadly Mumbai attacks of 2008.

  Zabiuddin Ansari, also known as Abu Jundal, was arrested on his arrival at Delhi airport on Thursday, Press Trust of India news agency said.

  He was deported from Saudi Arabia on India's request, reports said.

  Mr Ansari is being described as the "handler" of the 10 gunmen who carried out the assault on targets in Mumbai.

  The attacks claimed 165 lives. Nine gunmen were also killed.

  The sole surviving gunman from the attacks, Mohammad Ajmal Amir Qasab, was convicted of murder and waging war on India in May 2010 and given a death sentence.

  The police was quoted as saying by Press Trust of India news agency that Mr Ansari, 30, was arrested on 21 June, and remanded to police custody for 15 days by a city court on the same day.

  A resident of a village in the western state of Maharashtra, Mr Ansari allegedly taught Hindi to the gunmen who carried out the Mumbai attacks, Indian media quote security sources as saying.

  He left for Pakistan and later went to Saudi Arabia, they say.

  Reports say he was present in a "control room" set up the Pakistan-based militant group Lashkar-e-Taiba and guided the gunmen during his attack.

  The 60-hour siege of Mumbai began on 26 November 2008, targeting luxury hotels, the main railway station and a Jewish cultural centre.

  Relations between India and Pakistan deteriorated sharply after India blamed the Lashkar-e-Taiba for the attacks.

  After initial denials, Pakistan acknowledged that the assault had been partially planned on its territory and that Qasab was a Pakistani citizen.