Police may be arresting marginal terror suspects to clear decks for Olympics says watchdog

Mr Anderson told the BBC: “The Olympics are potentially a major target and you are seeing the police, perhaps in a marginal case what they might do is decide to intervene a little bit earlier.”

Six people continue to be questioned by the Metropolitan Police following arrests in east and west London last week.

Among the suspects was white Muslim convert Richard Dart, who was radicalised by cleric Anjem Choudary, and a former Met police community support officer and his two brothers.

A seventh person, a 30-year-old woman was released without charge on Saturday.

In a separate operation, West Midlands police arrested seven men after guns and a rudimentary improvised device were found hidden in a car.

The vehicle had been stopped by chance by police for having no insurance but the discovery was not made until it had been impounded.

It raised the suspicion that a group were planning an imminent assassination attempt.

The men continue to be questioned by police.

Labour last night accused Theresa May, the Home Secretary, of putting London at risk through watered down anti-terror measures.

It emerged yesterday that a suspected al Qaeda terrorist passed through the Olympic Park on five separate occasions despite being banned from doing so.

The 24-year-old, who can only be referred to as CF, was arrested for breaching the terms of his an order under the Terrorism Prevention and Investigation Measures Act – referred to as a "Tpim".

The man had previously been under a control order, which Tpims replaced, and under the previous regime was banned from London as a whole.

Following the new system he was allowed to return to live in the capital.

It was during this period that he allegedly took trains through the Olympic Park despite being banned from being in that area.

His movements were picked up because he has to wear an electronic tag and his lawyers insist that he only used the route to visit a solicitor dealing with his legal challenge against the order – due to be heard by the High Court today.

Shadow Home Secretary Yvette Cooper said the multiple breaches "raise very serious questions about the Home Secretary's judgment in downgrading counter terror powers in Olympic year against expert advice".

"Theresa May has very urgent questions to answer about how her decisions allowed this terror suspect who was previously banned from London to go repeatedly to Stratford, home of the Olympic Park," she said.

"The reports show that last year this terror suspect was seen as sufficiently dangerous for the Home Office and the courts to ban him from London.

"Yet this year, because the Home Secretary downgraded control orders to Tpims, he was allowed back into the capital and was able to travel to the Olympic area as a result.”