The Liverpool Remembrance Sunday bomber was trying to build a device similar to those used in the 7/7 London attacks prior to this weekend's attack, it is claimed.
Christian convert Emad Al Swealmeen, 32, spent months building up a supply of dangerous chemicals at a rented flat in the city, where he is believed to have attempted to make multiple explosives.
He was the only person killed as his bomb detonated in a taxi outside Liverpool Women's Hospital on Sunday morning.
Counter-terrorism sources told The Times that he attempted to construct a device using primary and secondary explosives to magnify the blast.
Similar bombs were used during the 2005 attack on the London tube, when four al-Qaeda inspired terrorists killed 52 innocent people in simultaneous attacks in the capital.
Yesterday streets around Al Swealmeen's flat were cordoned off after a package was discovered, with bomb disposal officers called to the scene.
Assistant Chief Constable Russ Jackson said Iraq-born Al Swealmeen had rented the home seven months ago and had started making "relevant purchases" for his homemade bomb "at least" since that time.
Mr Jackson said several suspicious packages were found, and were examined by explosive ordinance disposal (EOD) officers before being recovered by forensic teams.
The cordon was removed from Boaler Street yesterday evening, but Mr Jackson said the public may still see EOD officers in the area on Thursday "in case further items are found".
Searches have also been carried out at a property in Rutland Avenue that had been rented by Al Swealmeen since April, and that is the main focus of the police investigation.
Earlier, Mr Jackson said: "A complex picture is emerging over the purchases of the component parts of the device, we know that Al Swealmeen rented the property from April this year and we believe relevant purchases have been made at least since that time.
"We have now traced a next of kin for Al Swealmeen who has informed us that he was born in Iraq."
No evidence of terrorist ideology has yet been discovered, it is understood.
Mr Jackson said the bomber had suffered from periods of mental illness that will "form part of the investigation and will take some time to fully understand".
Mr Jackson added: "There is much comment in the media about Al Swealmeen and it is clear that he was known to many people. We continue to appeal for people who knew him, especially those who associated with him this year as we try and piece together the events leading up to this incident and the reasons for it.
"At this time we are not finding any link to others in the Merseyside area of concern but this remains a fast moving investigation and as more becomes known we cannot rule out action against others."
Last night The Mirror reported the cabbie who survived the Liverpool bomb attack told rescuers: “Someone has blown me up.”
Security guard Darren Knowles raced to help David Perry after terrorist Al Swealmeen set off his bomb.
He said: “I just grabbed him and tried to get him to safety.”
Brave security guard Darren desperately tried to find out if there was anyone else who could be saved as he helped David, the taxi driver whose cab exploded at a Liverpool hospital.
Reliving the horror of the Remembrance Day bomb blast, Mr Knowles, 50, told how the driver stumbled from his taxi, blood pouring from his ear and neck, screaming, “I want my wife”.
