The family of a Wycombe teenager who was arrested on suspicion of being involved in terrorist activity have spoken of their “shock” of his detention and defended the “good boy” who is currently in police custody.

A man named locally as Yousaf Syed, 19, was arrested in the terror raid in Desborough Avenue last Thursday evening.

He remains in police custody, along with three other men.

Mr Syed’s uncle, Nasar Mahmood, has defended his nephew and raised concerns of the actions of some in the community who have aided police and media in identifying members of his family.

Mr Mahmood said: “We are shocked at what has happened. Yousaf is a good boy and practicing Muslim and we can’t imagine that he would have anything to do with any alleged plot.

“We are outraged that pictures of the family were obtained without consent from any family members and were used in Sunday papers and we condemn the actions of... (the person) who did this and who has benefited financially.”

Some in the Muslim community have denounced police’s actions during the arrest, which saw about 40 officers swoop on the terraced property at about 8.45pm.

Saqib Deshmukh, from campaign group Justice4Paps, has criticised the “disproportionate” amount of police force used during the raid.

Mr Deshmukh said: “One of the concerns that we heard was that it was a disproportionate use of force and armed response. Did it necessitate that?

“Was there a need for that to happen? Was there an actual threat on the ground? And that's a concern – that the actual number of forces and the level of force used is disproportionate.”

The Metropolitan Police has declined to comment on the operation at this time.

Justice4Paps said that at the time of the raid there were five people in the house – Mr Syed, his mother, his two sisters and his younger brother.

Mr Syed’s home was raided in April. The teenager was not arrested but his passport was seized, according to community sources.

Justcice4Paps said Mr Syed was first approached by the police when he was 17 years old and has been visited by officers at his workplace.

Mr Deshmukh added: “We feel that this is continuing harassment of Yousaf and his family. In the context of the recent arrest and then release of Moazzam Begg we are extremely concerned about the arbitrary detention of Muslims.”

National media reported that eight people had gone missing from the town, yet Justice4Paps said they know nothing about this and are concerned about potential “scaremongering” in the community.

In a statement issued by the Wycombe Islamic Society (WISE), Sajjad Tameez said: “We would like to reassure people that no WISE mosque students are missing and we are not aware of any missing persons reports from the authorities.”

Justice4Paps said they could not see any “concerted” work being done on the ground to deal with the antagonism and tension that has been caused and the “inevitable rise in anti-Muslim attacks and harassment”.

Thames Valley Police’s Deputy Commander for Wycombe, Chief Inspector Scott Messenger, said: “This is an investigation being led by the Metropolitan Police’s Counter Terrorism Unit and local officers are assisting them.

“Terrorism in a national threat to the UK and I would urge residents to remain vigilant.

“If anyone from the local community has any concerns or information they can contact police on the 101 number or the Anti-Terrorist Hotline 0800 789 321; all calls will be treated with the strictest confidence.”