Sri Lankan authorities were carrying out a probe at its end to fill in the gaps in the investigations being carried out by India besides corroborating the version of Hussain.
Siddiq is not a new name for intelligence agencies as he figured earlier as well in 2012-13 when central security agencies picked up one Tameem Ansari, a frequent flier from Trichy to Colombo. Ansari was arrested after six months of surveillance in 2012.
Ansari, a small trader who sent, among other things, potatoes and onions to Sri Lanka, was in touch with Haji, a Tamil-speaking Muslim from Colombo.
Since Ansari's business was not doing well, Haji allegedly introduced him to Siddiq in the Pakistan mission in Colombo, and his second in command, Shaji.
After reportedly brainwashing him, Siddiq roped him to take videos of the Nagapattinam port, the ships that berthed there, the topography and other dimensions as well as Mallipattinam, traditionally a landing point.
The sources said the apparent strategy being followed by Inter-Services Intelligence (ISI) was to rope in Muslims from Sri Lanka for executing their plans to give credibility to the deniability factor that it was not involved in any way.