The two men were seemingly out of place in a shop full of shampoos, hair colourings, perfumes and potions.

They shuffled their feet, stretched their hands behind their heads, exchanged private remarks and smiled at one another as they waited for a shop assistant’s attention.

But these two men, Muktah Said Ibrahim and Manfo Kwaku Asiedu, were not buying hair mousse or perfume, a court was told yesterday.

CCTV images showed them acquiring the bulk quantity of liquid hydrogen peroxide that would allegedly be used to manufacture the July 21 bombs.

The footage of Mr Ibrahim and Mr Asiedu shopping in Pak Cosmetic Centre in Finsbury Park, North London, was played to a jury at Woolwich Crown Court.

The Crown alleges that the 208 litres of hydrogen peroxide bought at Pak was part of the 443 litres boiled down to make a concentrated solution that was the key ingredient of the bombs that partially exploded on three Tube trains and a London bus on 21/7.

Mr Ibrahim, the alleged bus bomber, and Mr Asiedu, who is said to have lost his nerve and abandoned his rucksack bomb in a park, watched the film from their seats beside one another in the dock.

The high-quality colour footage was recorded by cameras above the counters and tills in the giant cosmetics supply store in Stroud Green Road.

The two men and another of the alleged conspirators, Adel Yahya, had been in the shop on previous occasions discussing what strengths of hydrogen peroxide were commercially available and haggling over the price for a large order, the court was told.

Mr Asiedu and Mr Ibrahim had finally agreed to pay £5.20 per litre (an 80p discount) for an order of 208 litres of 18 per cent strength peroxide. It was to be supplied in 52 four-litre bottles packed into 13 boxes.

In searches after 21/7, police found 51 of the bottles from Pak in the bins at Curtis House, where the defendants allegedly had a bomb factory.

On Tuesday, July 5 — two days before suicide bombers killed 52 people in London in the 7/7 attacks — the two men drove to the shop in Mr Ibrahim’s silver Montego car.

The cameras apparently picked up both men as they walked to the counter. Mr Asiedu was dressed in a grey and black zip-up top over a blue T-shirt, black trousers and white trainers. Mr Ibrahim, who had a short beard, wore a pale short-sleeved shirt and dark trousers.

They waited for a few moments as other customers were served and were then led to another part of the store. Muhammed Atif, the salesman who arranged the order for them, appeared and greeted both men with a handshake.

Mr Atif, who appeared as a witness, said that he had been told that the men were engaged in building work and used the chemical for washing or bleaching wood.

On screen Mr Ibrahim, who had already paid a deposit of £100, produced £170 in cash from his pocket and handed it to a shop assistant. Then both men walked off to where their boxes of peroxide were waiting to be collected.

The two men, assisted by Mr Atif, reappeared again, flitting across the screen and pushing trolleys piled high with the boxes containing the chemicals.

Mr Atif said that high-strength liquid hydrogen peroxide was rarely bought and that a large order came “once in a blue moon”.

The order placed by Mr Ibrahim and Mr Asiedu was so unusual that Pak’s suppliers, a factory in Renfrew, Scotland, had to manufacture a new batch of the chemical.

Mr Atif said that Mr Yahya had been the first of the defendants to visit the shop.

“I showed him the peroxides and the strongest was 18 per cent,” Mr Atif said. “He asked me what was the maximum strength I could get him and I told him I would have to contact our suppliers and see if we could get any stronger.”

Mr Yahya, a former computer student at London Metropolitan University, who used to worship at Finsbury Park mosque, left Britain six weeks before 21/7 and was not arrested until he flew into Gatwick in December 2005.

Mr Ibrahim, 28, Mr Asiedu, 32, Mr Yahya, 23, Yassin Omar, 26, Ramzi Mohammed, 25, and Hussein Osman, 28, deny charges of conspiracy to murder and conspiracy to cause explosions. The trial continues.

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