July 7 bombers Mohammed Sidique Khan and Shehzad Tanweer's association with Omar Khyam was not revealed to the Old Bailey jury.

The judge, Sir Michael Astill, said it would be too prejudicial for the fertiliser bomb plot accused to be linked to the men who caused carnage in London.

Bugged conversations in England between Khan and Khyam were not played to the jury.

Khan and Tanweer's names were not used in court and Khan was referred to only as Ibrahim.

Khan was at a terrorist training camp in Pakistan with four of the accused in July 2003, a pre-trial hearing was told.

Khan and Tanweer travelled from their homes in West Yorkshire and were spotted at meetings with Khyam in southern England in February and March 2004.

Khan was spotted four times and Tanweer three times.

At a secretly recorded session on February 21 2004, Khan asked Khyam: "Are you really a terrorist?"

Khyam replied: "They are working with us."

Khan: "You are serious, you are basically...?"

Khyam: "I am not a terrorist, they are working through us."

Khan then told Khyam: "Who are? There is no one higher than you."

Khan said he was debating whether or not to say goodbye to his baby before going to Pakistan again.

Khyam told him: "I do not even live in Crawley any more. I moved out because in the next month they are going to be raiding big time all over the UK."

Khyam met Khan again on March 23 2004, a week before Khyam was arrested.

Khyam and Khan discussed passports and raising funds from as many banks as possible using fraud. Tanweer, Khan's right-hand man, was present.

Khan and Tanweer were planning the proposed trip to Pakistan with Khyam at that final meeting. Police believe Khyam was at the final stage of his bomb plans and was about to flee abroad.

Officers began to tail Khan from a February 2 2004 meeting with Khyam but later decided he was concerned only in fund-raising.

Khan later attended two other Pakistani training camps before leading the July 7 2005 bombers.

American supergrass Mohammed Junaid Babar was part of the cell and gave evidence against Khyam and six men accused of the fertiliser bomb plot.

He also told his FBI handlers of other British suspects, but was never shown photographs of Khan, whom he knew as Ibrahim.

It was only after the July 7 outrage that Babar saw Khan's picture and told his captors that this was "Ibrahim" from the July 2003 training camp.

Babar was reported to have been angered by the failure to show him surveillance pictures of Khan - a move which might have tipped police off that he was more of a security risk than they thought.

Reports from America say Babar told investigators that Ibrahim was "trouble" and "should be checked out".

Babar told the trial how people at the camp were taught to use arms, ammunition and explosives.

He said Khan was there with Khyam, Shujah, Akbar, Garcia and Khawaja.

Amin was said to have welcomed Ibrahim (Khan) and another man at an airport in Pakistan.

Khyam, who was there to meet others, had told Ibrahim and his companion about the camp and they, along with Babar, later travelled to it in the mountains.

Babar said: "We had just told them we had just set up a training camp and they were free and wanted to attend.

"Amin did not go because he was busy. He had already been to training."

Babar said Khan did not do explosives training, only firearms.

Khyam gave his own version of his meetings with Ibrahim during the trial.

He said Ibrahim travelled with him to the camp and watched weapons training for a couple of days.

Khyam said he met Khan and another man by chance at the airport and they talked about Afghanistan.

"I thought that as Amin was coming to collect them, they were probably sympathetic to the cause," he said.

A couple of days later, he, Babar, Ibrahim, and three others set off in a small hired van.

They camped out overnight on a mountain before getting to the training camp in Malakand.

"It was almost finished. There was some firing," said Khyam. Various videos had been made.

Early in 2004, Khyam planned to go back to Pakistan in two groups with five other men, including Ibrahim.

"He was going to travel with me and two of his friends," said Khyam.

He said Khan and his associates had also been raising funds by loan and credit card fraud. They all planned to bring money and equipment to Afghanistan.

The prosecution had wanted Khan and Tanweer's identities revealed, but were over-ruled by the judge who said it would not help prove the charges.

The judge was told that: Khyam was caught on secret video and audio recordings meeting Khan and Tanweer on February 2 2004; On February 21 2004, Khan was recorded talking in a car driven by Khyam; A week later on February 28 2004, Khyam was in a car with Khan and Tanweer. The car was normally driven by Khan; On March 23 2004, they were seen getting out of Khyam's car; Photographs were taken of them on some of these occasions; Police officers who listened to the taped conversations concluded that they were "concerned with the fraudulent raising of funds rather than acts of terrorism"; Khan attended other training camps and his movements between the meetings and July 7 were not fully known; Banning the use of the two bombers' real names from the trial, Sir Michael said it was not known what influences there had been on Khan in that time.