Bomber's video shows hand of al-Qa'ida

Tanweer's last testament, like Khan's in September, features a statement from Ayman al-Zawahiri, al-Qa'ida's second-in-command, bears the stamp of al-Qa'ida's video production company, and includes a contribution by the American Adam Gadahn, believed to be running the group's propaganda operation. But it is also possible al-Qa'ida has appropriated Tanweer's video as a publicity stunt. Though it probably helped train the London bombers, no evidence points to a controlling al-Qa'ida mastermind behind the attacks.

Tanweer vows that the attacks will continue until troops are pulled out of Iraq and Afghanistan and "you stop your support" for America and Israel. "What you have witnessed now is only the beginning," he says.

The recording, released to the Arab television station al-Jazeera to coincide with the anniversary of the bombings, provides an insight into Tanweer's indoctrination by Khan, the primary-school mentor who attracted him and others to a youth club at the Hardy Street mosque in Leeds and, amid the boxing and pool sessions, plied them with stories about abuse of Muslims.

In the video, Tanweer insists that British non-Muslims must die because they elected the government that has perpetrated atrocities against Muslims. This is an echo of Khan's mantra, in his video: "Your democratically elected government continues to perpetrate atrocities."

Tanweer, who killed himself and seven others in the Aldgate Tube bomb, is seen wearing a red and white chequered headdress identical to the one that Khan wore in his video. He points animatedly at the camera, as did his mentor. Yet Tanweer seems less confident than his leader: while Khan stared straight at the camera throughout, Tanweer looks down, presumably at a script. Both videos feature the same background, which suggests they were made at the same time ­ possibly during visits to Pakistan and Afghanistan they made together in November 2004 and early 2005.

Neither man mentions the plot to attack London's transport system so it is impossible to determine whether they devised their operation with terrorist leaders during their stay, or on their own once they returned to the UK.

The video is cut with footage of people mixing chemicals to make bombs and images of a man circling points on a map of London with a black pen. There is also footage of militants with firearms, while Zawahiri appears with a sub-machine gun propped up on the wall behind him.

A third man featured in the video apparently refers to the 2 June police anti-terror raid in Forest Gate, east London ­ suggesting that al-Qa'ida video technicians put the tape together in the past five weeks.

Tanweer's video underlines his seniority in the bombing team. Though known affectionately to his family as Kaka (little one), the 22-year-old son of a chip shop owner was a highly focused jihadist. He is believed to have travelled without Khan to at least one terrorist training camp near the Kashmir border in Pakistan, in January 2005. He and Khan became known to the security services on the "periphery" of surveillance operations before the bombings, but no further investigation took place.