Zaidi in his upcoming book, 'Headley and I', claims that Pakistan born US national had visited Matoshree, the residence of the Thackerays at suburban Mumbai. After visit to Matoshree, Headley claimed that Bal Thackeray was a "sitting duck".
Mocking at the security arrangement for Sena chief, Headley had asserted that he found loopholes in the late Sena chief's security at his residence. According to the book, Headley had made a smooth entry to Matoshree with the help of a Sena activist Vilas.
"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," said Headley after visit to Matoshree.
The book also claims that Headley had visited the Sena headquarter at Dadar for a video surveillance. The 26/11 conspirator had met Sena public relations officer Rajaram Rege and sought information while posing as an immigration agent.
The book is believed to have focused on Headley's controversial friendship with Bollywood director Mahesh Bhatt's son Rahul who allegedly had hosted Headley during his Mumbai visit.
Headley had gone to the famous Siddhivinayak temple with Vilas and Rahul, 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 Nov 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 Mar 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.
(With PTI inputs)