Clutching his baby daughter to his chest and speaking in barely a whisper, the young father explains that he is off to war in Afghanistan and will never return.

For 80 seconds yesterday morning, Mohammad Sidique Khan, the ringleader of the July 7 suicide bombers who killed 52 people, was seen as a loving father, cradling his daughter as he bids her farewell.

The previously unseen footage, shown at Kingston Crown Court, depicts Khan gently stroking baby Maryam’s hair, expressing his affection and explaining why he is sacrificing his life. He asks her to look after her mother, and urges her to “learn to fight” when she grows up.

“Sweetheart, not long to go now,” he says. “And I’m going to really, really, miss you a lot. I’m thinking about it already. Look, I absolutely love you to bits and you have been the happiest thing in my life. You and your mum, absolutely brilliant. I don’t know what else to say.”

The recording was made soon after Khan had said his 6am prayers on November 16, 2004. Two days later he travelled to Pakistan to fight against forces including British and American troops in neighbouring Afghanistan. He had accepted that it would be a “one-way ticket” and had asked to delay the trip until his daughter’s birth in May, the court has heard.

The footage shows that in the six months they were together, Khan had developed a close attachment to his only child. Sitting on a bed at his wife’s family home with Maryam in his lap, Khan says: “I just wish I could have been part of your life, especially, these growing up — these next months, they’re really special with you learning to walk and things.

“I just so much wanted to be with you but I have to have to do this thing for our future and it will be best, inshallah, in the long run. That’s the most important thing.”

Bending his head he kisses his daughter’s hair before continuing: “But most importantly I entrust you to Allah and let Allah take care of you. And I’m doing what I’m doing for the sake of Islam, not, you know, it’s not for materialistic or worldly benefits.”

Later in the recording his wife, Hasina Patel, is heard saying that the tape has almost come to the end, warning: “There are two minutes left so say your piece.” Khan continues: “Maryam, my little sweetheart, I love you lots and lots. You are my little baby with big fat little feet.

“Remember me in your duas [prayers], I will certainly remember you, and, inshallah, things will work out for the best . . . Maryam be strong, learn to fight — fighting is good. Be mummy’s best friend. Take care of mummy — you can both do things together like fighting and stuff.”

The court was also shown footage taken a month earlier of Khan introducing Maryam to her “uncles” — fellow London bombers Shehzad Tanweer and Hasib Hussain and their alleged conspirator Waheed Ali.

A week after Khan, 30, and Tanweer arrived in Pakistan they changed their plans and decided to turn their attention to an attack in Britain, it is alleged. Both men, it is said, returned in February 2005 and carried out the London bombings five months later.

Mrs Patel handed the video tapes to a friend who passed them to police in the aftermath of the 7/7 bombings in which Khan killed himself and six other Tube passengers on the Circle Line at Edgware Road.

It was played yesterday during the trial of the London’s bombers’ alleged conspirators, Mr Ali, Sadeer Saleem and Mohammed Shakil. All three men, from Beeston, Leeds, deny the charges of conspiring to cause explosions on the London transport system.

The trial continues on Monday.

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