All six suspected Lashkar-e-Tayiba members, arrested in connection with the July 11 serial blasts in Mumbai, are likely to be subjected to scientific tests including narco-analysis to probe their involvement in the explosions, police said in Mumbai on Wednesday.

"We may subject the suspects to scientific tests to ascertain their involvement in the serial blasts," Mumbai Police Commissioner A N Roy said.

Roy said investigators are confident that those arrested are part of two separate LeT modules and want to know whether the six are involved in the serial blasts or if they know of any other module that may have been involved in the blasts.

With a limited time for police custody at their disposal, the Anti-Terrorism Squad wants to interrogate the suspects as quickly as possible and get details on the planning and execution of the blasts that killed 200 people and injured over 600, police sources said on Wednesday.

While scientific methods of investigation like lie-detector and brain-mapping tests can be used as evidence, other tests like narco-analysis help collect valuable information, the sources said.

In case the police decide to conduct the tests, it will have to move the local court and seek its permission.

Since not many forensic laboratories have testing facilities, the ATS will also have to take prior appointment at forensic science laboratories that perform the tests, the sources said.

The ATS has arrested six suspected LeT members so far.

Kamal Ansari and Khalid Sheikh were arrested from Bihar and Mumtaz Choudhary from Navi Mumbai last week.

Tanvir Ansari, a medical practitioner was arrested on July 24, while Jamir Sheikh and Sohail Sheikh were arrested late on Tuesday night.

Police sources said that Kamal, Khalid and Mumtaz belong to an LeT module with contacts in Nepal and Bangladesh, while Jamir and Sohail are part of the module headed by Tanvir Ansari.

The ATS has maintained that the persons arrested so far have been held on suspicion and it has no direct evidence yet to connect them to the seven serial blasts.