The family was caught after being placed under covert surveillance by police following the discovery of the body of worker Christopher Nicholls, 40, in 2008.

BBC: Connors family forced labour sentences appealed

The United States and others have expressed concern that Tehran is trying to operate a covert nuclear weapons program under the guise of a nuclear energy program.

CNN: Netanyahu: Putting politics aside

This followed the exposure last year of the covert system of referral fees, under which insurers, in effect, stoke up claims against themselves and thus drive up premiums.

BBC: Car insurance facing Competition Commission study

The latest investigation comes after the exposure last year of the covert system of referral fees, under which insurers, in effect, stoke up claims against themselves and thus drive up premiums.

BBC: Car insurance market referred to Competition Commission

In the UK, the availability of cheap GPS devices, and a mistaken belief that it was permitted under the Regulation of Investigatory Powers Act, led to covert tracking being used by public authorities, including local councils "without properly considering the application of the legislation, " according to watchdog the Surveillance Commissioners.

BBC: How much privacy can smartphone owners expect?

Would it be a member of the criminal underground or covert national operative in another region of the world, acting under orders?

FORBES: Intellectual Property Theft: Beware The Enemy Within

Mahdi Obeidi, who used to run Iraq's covert uranium enrichment programme and had been famously ordered to hide the plans under a tree in his garden, concurs.

ECONOMIST: But there was still plenty going on that shouldn't have been