"Such a control room could not have been set up without some kind of state support," he said at a press conference here.
Jundal, 30, arrested here on Jun 21 on his arrival from Saudi Arabia, had found a "very safe haven" in Pakistan, he said.
Jundal is being interrogated by Delhi Police and security agencies to ascertain all aspects of the conspiracy behind the 2008 Mumbai attacks that left 166 dead including some foreigners.
About the presence of others in the control room and whether Saeed was also there, Chidambaram said, "Yes, others were present and we think one of them was Hafiz Saeed."
He termed Jundal's arrest as an "important development" as far as the investigations in the 26/11 Mumbai terror case were concerned.
"In fact many of the missing pieces of the 26/11 conspiracy are now known to us through interrogation of Abu Jundal. He was a key operative, he was assigned the key responsibility of putting the 10 terrorists to intensive training and the customs followed by Mumbaikars.
"He was the key person who briefed the 10 persons including Ajmal Kasab and he had an important role in the control room," he said.
Taking a potshot at Pakistan's Interior ministry chief Rehman Malik that Jundal was an Indian, he said, "I agree with Rehman Malik that Abu Jundal is an Indian and perhaps he was radicalised in India. I admit that."
Equally, Pakistan should admit that Jundal did go to Pakistan and was part of the group which trained and prepared Kasab and nine others and he was in the control room as one of the masterminds and handlers of the (26/11) attacks.
"Just as we admit the facts Pakistan too should admit the facts," he said.
Asked to share some information about Jundal's interrogation, Chidambaram said, the security agencies had come to know that training was given at one place while the control room was established at another place and infrastructure was provided.
"All this indicated that these activities could not have been carried out without some kind of state support. That is a logical inference we have to make. It is only when his interrogation is completed we will come to know who gave what support. At the moment he is being interrogated," he said.
The home minister dismissed reports of rift within security agencies and police forces of various states and said Syed Zabiuddin Ansari alias Abu Jundal was a suspect or an accused in several cases.
These included the Ahmedabad Railway station blast of Feb 19, 2006, the Aurangabad arms haul of May 2006 and the German bakery blast case.
"No one is fighting anyone. At the moment, the custody of Jundal has been given to Delhi Police and investigation agencies and intelligence agencies have joined Delhi Police in interrogation.
"I have told the chief minister of Maharashtra in due course with the permission of the court he will be made available to the ATS Mumbai and to the Maharashtra Police in Mumbai and Aurangabad cases," he said.
Chidambaram said Jundal would be in due course made available to Gujarat Police in the Ahmedabad railway station blast case.
Asked about reports that Jundal was planning a strike at Mohali during a cricket match between India and Pakistan, he said, the match was fully secured.
"There was no threat, I repeat there was no threat either to the Prime Minister of India or to the visiting Pakistani dignitary," he said.
Home Secretary RK Singh said, Pakistan should admit that they have given passport and two identity cards to Jundal and that they should also admit the fact that they claimed that he was a Pakistani.
Asked about the initial confusion that he was Abu Hamza, Chidambaram said, "Abu Hamza, Abu Jundal, these are pseudonyms. In fact, there are many people who use the same pseudonym in different times."