Journalists have to consider breaking the law on occasion in order to "shed light" on wrong doing, the head of Sky News has told the Leveson inquiry, as Ofcom investigates claims the broadcaster hacked into emails.
But John Ryley, head of Sky News, told the Leveson Inquiry that such occasions would be "very, very rare".
Ryley was speaking as the latest phase of the inquiry into press ethics - overseen by Lord Justice Leveson - began in London.
He was asked when Sky News might consider breaking the law in pursuit of stories.
"Journalism is at times a tough business," he said. "And we need at times to shed light into wrongdoing. There may be an occasion. It would be very, very rare."
At the Leveson inquiry into media ethics Ryley was probed about the occasion when one of his reporters hacked the email account of back-from-the-dead canoeist John Darwin.
Ofcom confirmed today that it is investigating the "fairness and privacy issues" raised by the hacking.
When the incidents emerged just under three weeks ago, Sky News defended its actions as being in the public interest and said it amounted to "responsible journalism".
But a spokesman for the media regulator said on Monday: "Ofcom is investigating the fairness and privacy issues raised by Sky News' statement that it had accessed without prior authorisation private email accounts during the course of its news investigations."
A spokeswoman for Sky News said: "The Crown Prosecution Service acknowledges that there are rare occasions where it is justified for a journalist to commit an offence in the public interest.
"The director of Public Prosecutions Keir Starmer told the Leveson inquiry that 'considerable public interest weight' is given to journalistic conduct which discloses that a criminal offence has been committed and/or concealed."
Darwin, 61, faked his own death in a canoeing accident in 2002 so his wife could claim hundreds of thousands of pounds from insurance policies and pension schemes.
The evidence discovered by North of England correspondent Gerard Tubb was handed to police and used in the successful prosecution of Darwin's wife Anne, 60, for insurance and pension fraud.
The Darwins, from Seaton Carew, near Hartlepool, were jailed at Teesside Crown Court in 2008 for the swindle, which deceived the police, a coroner, financial institutions and even their sons, Mark and Anthony.
On Monday the Leveon inquiry heard how Tubb learned from a "source close to the prosecution" that an email account used by Darwin was not going to be used as evidence.
Ryley said Tubb had accessed the account in June 2008 while working on a "court backgrounder" to go out at the conclusion of the trial.
"He had been working on it for five to six months," Ryley said.
"It became apparent that the email account would not be used by the prosecution.
"John Darwin had been using emails to go about his business in the five years that he had disappeared.
"Sources close to the prosecution made clear that they were not going to be following up on the emails."
Ten days after accessing the account, the findings were reported to the police.
The detail was "pivotal" in the case against the fraudsters, the inquiry heard.