Guardian

Key to the investigation was the search for more details about how the association among an apparently disparate group of people came about. Locals said they did not know of any radical organisations that might have been a unifying factor. The widespread assumption was that they were joined by geography. Many of the houses raided are in close proximity.

One of the figures being singled out for intense scrutiny was Umar Islam, 28, formerly known as Brian Young, who was arrested in London in the early hours of Thursday morning but grew up in High Wycombe. Anti-terrorist squad officers are examining the possibility that he may have provided a link between the group detained in London and those arrested in Buckinghamshire. Yesterday his mother Sylvia expressed disbelief at the arrest. "I don't even believe it," she said.

A neighbour, Parkhash Dhanjal, 62, said Mr Islam had married a Muslim and the couple had a son. He wore shalwar kameez to the mosque and had grown a beard, she said. Mrs Dhanjal said: "The family are nice and Brian is a good boy."

While officers searched his family home in High Wycombe, forensic experts were also examining the property owned by his in-laws in Plaistow, east London. Neighbours told how his wife had changed around the time they met. "She was a lovely, independent young woman but she suddenly changed," one resident said.

There was also renewed focus on Waseem Kayani, 29, who is thought to work as a taxi driver in High Wycombe. He lived in the Downley area, to the west of the town, where his was the only Asian family in the street.

A neighbour, Brian Ashby, 41, said the family, who have a number of daughters, were "one of the quietest" in the neighbourhood. "They were led out of the house and were carrying bags of clothes, not under arrest, and they left in their own cars," Mr Ashby said.

Mr Kayani is thought to have been friends with two of the other men arrested in High Wycombe, Assad Sarwar, 26 and his older brother Amjad, 28. It is believed that materials have since been taken from the Sarwars' semi-detached ex-council house.

The older brother, who was known locally as "Valentino" apparently came late to a more radical version of his faith. In 2003 he advertised himself on an internet dating agency, describing his virtues as honesty and his likes as fish and rap music. He worked in car sales which may have forged his link with Shazad Khuram Ali, 27, who lives about half a mile away, to the east of the town. Mr Ali ran a car import business, AKZ, trading from his home in Micklefield Road. Ali Hussain, 19, said the men were friends.

His incredulity was echoed by others, including Shaukat Warraich, a local community leader, who told a police press conference of his shock at the arrest of Abdul Waheed, a convert formerly known as Don Stewart-Whyte, 21. Mr Waheed, whose late father was a Conservative party agent, was seen by neighbours being escorted from his home in Hepplewhite Close. He is a half brother of the catwalk model Heather Stewart-Whyte.

"He converted to Islam quite recently and just two weeks ago attended an inter-faith dialogue meeting where he spoke freely about his conversion and spoke freely to people of all faiths there, Hindu, Christian, Muslim alike," Mr Warraich said. "It is very difficult to imagine that individual holding radical views."