The Mail gets a scoop this morning with the news that

"Up to eight police officers and civilian staff are suspected of links to extremist groups including Al Qaeda.
Some are even believed to have attended terror training camps in Pakistan or Afghanistan.
Their names feature on a secret list of alleged radicals said to be working in the Metropolitan and other forces. "

It has managed to get its hands on a secret list drawn up by Mi5 and the paper believes that the site of the second bomb in London may have come about after these insiders obtained information about evacuation procedures

"

The Daily Mail can reveal that the second device parked near
Haymarket was left at a designated "evacuation assembly point" where civilians
and the emergency services would have gathered had the first bomb gone off.
Investigators are trying to establish whether the bombers knew the
significance of the location

The paper adds that

it is understood that a policeman was removed from his post
after concerns about his conduct in the aftermath of a major anti-terrorist
operation in the past two years.
For legal reasons, the Mail cannot reveal
any more about the case.