British investigators continue to dig for details in the News Corp. hacking scandals.

Reuters news service columnist David Cay Johnston, meanwhile, says an investigation of the company's public financial figures shows it has consistently made money at tax time over the past four years. And, he says, it's all legal.

Johnston says the company's tricky accounting has netted it billions of dollars.

"News Corporation made over $10 billion in profits over the last four years. And their tax came to $4.8 billion, negative," Johnston says. "That is, they made $4.8 billion from tax refunds."

Other companies, including GE, have achieved similar feats before, Johnson says. GE managed not to pay any taxes last year. But most don't make billions in profit, he adds.

It would "... increase their profits, if you looked at it that way, by almost 50 percent," Johnson says of News Corp.

Johnston says News Corp. was able to use the system in its favor by taking advantage of a few corporate tax laws. One provision allows a company to reach back and carry forward tax losses and benefits from many years.

"The second thing that Mr. Rupert Murdoch does that's very important is ... [use] tax haven subsidiaries," he says. "And when you have a tax haven subsidiary — the Cayman Islands, Bermuda, Panama — what you do is you take expenses in the United States, and then you take the profit in the tax haven where they don't pay a tax on it."

Utilizing off-shore havens, News Corp. was able to show the IRS a theoretical loss, even though it made money, Johnson says.

"You look to investors like a gold-plated company and look to the IRS like you're a moth-eaten failure," Johnston says.

He says it's not unusual for companies to make money on their taxes, but it's not the standard either.

"For all but the 12,000 largest companies in America — those are ones that are worth billions of dollars, they're household name companies — the corporate tax every year runs about 32 percent of profits and the rate's 35 [percent]. So they're paying their full bill," he says. "For the very biggest companies, the average is less than 20 percent."

But Johnston says there's nothing illegal in News Corp.'s accounting.

"That's the scandal — is that it's legal to do many of these things. Hacking into people's cell phones, interfering in murder investigations, paying off Scotland Yard cops, that's a crime," he says. "But the tax material, the scandal is the law that they simply exploit brilliantly by hiring really smart people to do i

do it."