John Darwin was reported missing in March 2002. His wife, Anne Darwin, collected more than £500,000 in life insurance while he hid in their marital home. The pair even allowed their two sons to think he had died at sea.

A spokesman for Sky News said that police “absolutely knew” the emails – which the broadcaster passed to officers working the case – had been obtained by hacking.

Sky News insisted that the decision to hack into Darwin’s email was in the public interest and was an example of “responsible journalism”.

In a statement, the broadcaster said: “We stand by these actions as editorially justified and in the public interest.

 “We do not take such decisions lightly or frequently.

“They require finely balanced judgement based on individual circumstances and must always be subjected to the proper editorial controls.”

It has emerged that in the run-up to the 2008 trial that found both Darwins guilty of deception, former Sky News managing editor Simon Cole agreed that correspondent Gerard Tubb could hack into the Darwins’ Yahoo! email account.

Tubb discovered messages that cast doubt on Anne Darwin’s claim she had been forced to commit the fraud by her “domineering” husband.

Sky News has argued that this material – which it supplied to police – was pivotal to the court case.

It is illegal to hack into emails under the Computer Misuse Act.

Labour MP Tom Watson – a vocal critic of Rupert Murdoch’s media empire – said: “The chair of BSkyB needs to say something on this and reassure viewers this has not been going on more widely.”

Sky News also admitted to hacking the email of a suspected paedophile and his wife.

Picture: Getty