Mumbai terror attack conspirator David Headley, who had surveyed most of the 26/11 targets, had also conducted a recce of Bal Thackeray's heavily-guarded residence `Matoshree' in suburban Bandra in 2008, and found that Shiv Sena chief was a "sitting duck".
In his soon-to-be-released book, Headley and I, about filmmaker Mahesh Bhatt's son Rahul's unusual friendship with Headley during the latter's stay in Mumbai, author-journalist Hussain Zaidi has revealed how the LeT operative scanned Thackeray's residence with the help of Shiv Sena activist Vilas, a gym instructor.
Pakistani-American Headley frequently visited a gym in south Mumbai where Rahul Bhatt and Vilas worked out, and befriended them.
Headley, according to Zaidi, found loopholes in the late Sena chief's security at Matoshree.
The book -- to be released within a week, Zaidi told PTI -- also reproduces Headley's statements recorded by the National Investigation Agency (NIA) in Chicago.
According to Zaidi, the book tells how Headley once even visited Matoshree and photographed it for 15 minutes, posing as `a fan'.
Post-Matoshree visit, Headley told Rahul that Thackeray was "a sitting duck".
"A small bunch of desperadoes can break that security cover and reach Thackeray. I have no idea why the police are so proud of the protection he has been given," Headley is quoted as having said.
During reconnaissance of several targets in the metropolis, the Pakistan-origin US national, who had learnt to play golf in Lahore, made a visit to Willingdon Club here too, and termed a possible strike on the posh club as "icing on the cake".
Zaidi said the book also talks about Headley's visit to Shiv Sena headquarters in Dadar for a video surveillance. Posing as an immigration agent, he had met Sena public relations officer Rajaram Rege and befriended him.
Headley also went to the famous Siddhivinayak temple with Vilas and Bhatt, from where, under instructions from his bosses in Pakistan, he bought several red `maulis', later also seen tied around 26/11 gunman Ajmal Kasab's wrist, says the book.
The day hotel Marriott was bombed in Islamabad, Headley had told Rahul to "watch out" for a similar attack in Mumbai.
The Marriott Hotel bombing occurred on the night of 20 September 2008, when a dump truck filled with explosives blew up, killing over 50 people.
On November 10, 2008, sixteen days before 26/11, the LeT operative called Rahul by a satellite phone and specifically advised him against venturing into south Mumbai over the next few days, according to Zaidi. After the attack, Headley called to ask if Rahul and his family were safe.
A few months later, as the investigators probed the case and accessed phone intercepts, Rahul was picked up by NIA in connection with the 26/11 terror strike.
Headley, on March 18, 2010, pleaded guilty to charges of conspiracy in the Mumbai terror strike and plotting to attack a Danish newspaper which had published controversial cartoons of prophet Muhammad. He struck a plea-bargain deal with the US authorities.
On November 26, 2008, Ajmal Kasab and nine other Pakistanis, indoctrinated and trained by LeT, landed in Mumbai and went on a shooting spree at various places including the Taj Mahal Hotel and CST railway station, killing 166 people.