A jury heard that 24-year-old Waheed Ali was with the bomb ringleader Mohammed Siddique Khan when he made a number of visits to a major terror suspect who was under surveillance by MI5.

Ali, who is accused with two other Leeds men of checking out potential targets for the devastating attacks, can be heard in a bugged conversation in which the terrorist, known only as Ausman, tells Khan: "This is a one- way ticket, bruv".

Ali and his friends Sadeer Saleem, 27, and Mohammed Shakil, 31, all from Beeston, Leeds, are on trial for plotting with the bombers, but were not arrested until last year.

At Kingston Crown Court in London yesterday, the jury was told how the three close friends of the July 7 bombers visited famous London landmarks as they checked potential bomb targets.

The group, along with bus bomber Hasib Hussain and Tube bomber Jermaine Lindsay, took in the London Eye, the Natural History Museum and London Aquarium on what the prosecution claim was a two-day reconnaissance trip ahead of the bombers' deadly mission. The attacks claimed the lives of 52 people and injured hundreds more.

The court heard that the places visited by the five men bore a "striking resemblance" to the four locations of the bombings less than seven months later.

Harrowing images of the destruction caused by the blasts were released for the first time in court yesterday. Watched by families of those who died, closed circuit TV footage was played which showed people quietly making their way to work on a normal day before the terrorists struck.

The film, clearly displaying the date 7/7 in the top left-hand corner, showed people waiting on the platform as the doomed Aldgate Tube train pulled into the station just before 8.50am.

Thirty seconds later, as Shehzad Tanweer detonated his bomb, the camera shakes and clouds over as the station fills with smoke.

The court heard that the three defendants were extremely close to the bombers – in a video clip where Khan cradles his baby daughter Maryam, he introduces Ali and bombers Hussain and Shehzad Tanweer as her "uncles".

One text message from Ali to Khan said: "Gates of memories I will neva close. How much I will miss you no one knows. Tears in my eyes will wipe away but the love in my heart for you will always stay."

The court heard each of the defendants had extremist material at their homes when arrested, and a picture was discovered of Ali in a T-shirt with the logo: "Warriors of Allah".

Ali travelled to Pakistan with Khan in July 2001 and returned to Britain with him in September 2001.

Neil Flewitt QC, prosecuting, said the court also would hear from a convicted terrorist in prison in the US, Mohammed Junaid Barbar, that he met Khan and Shakil in Pakistan.

Mr Flewitt said Barbar had told the authorities they were there with Ausman, and told him they wanted to fight jihad.

The court heard that before Khan went on another trip to Pakistan, this time with Tanweer in November 2004, he made a video saying goodbye to his daughter.

It is thought he was going to fight jihad and believed he would never come home. But the prosecution said something changed Khan's mind and he returned to Britain in February 2005.

Mr Flewitt said: "It was, as you know, on the 16th December 2004... only a relatively short time after Mohammed Sidique Khan's unexpected decision to return to the UK, that Waheed Ali, Sadeer Saleem, Mohammed Shakil and Hasib Hussain travelled to London to meet Jermaine Lindsay and to carry out what, we suggest, was an essential preparatory step in the revised plan to bring death and destruction to the UK."

The trial continues.