People familiar with the matter tell Bloomberg that Apple’s handling of the matter remains under scrutiny and that company directors Art Levinson and Bill Campbell had been briefed by Jobs’s doctors on his medical condition at the time of the January disclosures, but little else.

Now, the path from “Steve is suffering from a common bug” to “a hormone imbalance has been robbing Steve of the proteins his body needs to be healthy” to “Steve has undergone a liver transplant” is obviously something of an eyebrow-raiser. But whether it was material to Apple’s business and therefore required disclosure isn’t clear. After all, Apple (AAPL) did just fine while Jobs was on sabbatical; the debut of new Macs, iPods and iPhones is testament to that. Beyond that, there’s this: Apple’s stock posted a 59 percent gain while he was away.

“The issue is not going to be whether they needed to disclose the medical records,” James Cox, a securities law professor at Duke University, told Bloomberg. “It’s going to be whether they monitored the disclosures about his health, in relation to investor expectations that Apple would continue to be led by Steven Jobs….[Apple] did fine. Do you need to say more than, ‘Our CEO has health problems and he’s out on leave?’ The question I think the SEC is looking at is whether it’s material.”

People familiar with the matter tell Bloomberg that Apple’s handling of the matter remains under scrutiny and that company directors Art Levinson and Bill Campbell had been briefed by Jobs’s doctors on his medical condition at the time of the January disclosures, but little else.

Now, the path from “Steve is suffering from a common bug” to “a hormone imbalance has been robbing Steve of the proteins his body needs to be healthy” to “Steve has undergone a liver transplant” is obviously something of an eyebrow-raiser. But whether it was material to Apple’s business and therefore required disclosure isn’t clear. After all, Apple (AAPL) did just fine while Jobs was on sabbatical; the debut of new Macs, iPods and iPhones is testament to that. Beyond that, there’s this: Apple’s stock posted a 59 percent gain while he was away.

“The issue is not going to be whether they needed to disclose the medical records,” James Cox, a securities law professor at Duke University, told Bloomberg. “It’s going to be whether they monitored the disclosures about his health, in relation to investor expectations that Apple would continue to be led by Steven Jobs….[Apple] did fine. Do you need to say more than, ‘Our CEO has health problems and he’s out on leave?’ The question I think the SEC is looking at is whether it’s material.”

The Steve Jobs health story takes yet another twist, this time a happier one: The Wall Street Journal is reporting that the Apple CEO underwent a liver transplant earlier this spring and is recovering from the operation.

Jobs, who stepped away from day-to-day management of his company in January, is still expected to return to work later this month, the Journal said.

The transplant, which the Journal says Jobs received “about two months ago,” may be related to a form of pancreatic cancer that the Apple (AAPL) CEO has been living with since 2003. In 2005, Jobs declared that he was “fine,” but the state of his health, or lack thereof, has been the subject of recurring speculation for years.

That reached a fever pitch during the past 12 months, spurred on by his unusually gaunt appearance at Apple’s 2008 Worldwide Developers Conference. Apple officials originally said Jobs was suffering from a “common bug.”

In January, following Jobs’s announcement that he was receiving treatment for a “nutritional problem” stemming from a hormonal imbalance, Bloomberg reported that he was considering a liver transplant.

Jobs’s response: “Why don’t you guys leave me alone–why is this important?”

The Journal says that Jobs, who was supposed to come back to work full-time by the end of this month, may ease into the role and that COO Tim Cook, who has been running the company day to day in his absence, may get more responsibility.

But the paper also says Jobs has been back to the company’s Cupertino, Calif., headquarters:

“During his leave, Mr. Jobs has remained involved in key aspects of the company and reviewed products and product plans from home. He has also been seen at Apple’s headquarters, according to people who have seen him there.”

Early this morning, Bloomberg reported that regulators are looking into Apple’s disclosures about the health–or lack thereof–of its iconic CEO Steve Jobs.

According to the story, the Securities and Exchange Commission is conducting a review of Apple (AAPL) “to ensure investors weren’t misled, a person familiar with the matter said. The Securities and Exchange Commission’s review doesn’t mean investigators have seen evidence of wrongdoing, the person said, declining to be identified because the inquiry isn’t public.”

And while BoomTown has railed against the creepy obsession the media have had with Jobs’s health and the publishing of rumors and innuendos about it as fact without a whole lot of reporting, I hope it is true.

It is also entirely appropriate that the government agency charged with keeping an eye on public companies does investigate–at the very least, to get the story right.

Because if the press and blogosphere and Apple aren’t going to do it, I vote for the one with subpoena power to sort it all out and make some levelheaded determinations about the rules of the road.

(And, frankly, it is good to see the SEC more vigorous after its stunningly moribund record of late–Hello, Bernie Madoff!)

Apple’s COO and acting CEO Tim Cook, by the way, will likely be questioned about the SEC look-see, Steve Jobs’s health and more at its first-quarter conference call at 2 p.m. PST today.

Of course, the health of its business is the most important thing–sales of iPods and iPhones, new products and what Apple will do with its $25 billion cash horde.

But the focus will surely be on Jobs and now, this government inquiry.

What will be most interesting is exactly how much companies do have to reveal about the health of their leadership and whether the relative fame and brand-critical nature of that exec matters more.

For example, do leaders like Jobs or, say, Martha Stewart, have more need to discuss their health than some lesser known CEO who might have a similar problem?

And since it has been well known that Jobs suffered from a bout with pancreatic cancer and recovered, does he have to disclose it all, given that even his curable version of the illness has complications that are well documented?

And, most of all, how specific do Apple and Jobs have to be, and how frequently do they have to update, especially since a diagnosis is always a moving target?

More to the point, given that the bordering-on-crazed attention given to Jobs–who engenders so much passionate emotion–has also been off-putting and, worse, all over the map in terms of accurate information, what clarity can regulators provide?

Apple has been under increasing pressure, since Jobs revealed he had a “hormonal imbalance,” soon after which he announced that he was taking a five-month medical leave from his duties because his health problems were “more complex.”

I am less strident than others on this turn of events since having accurate health information about yourself is not quite the same as, say, details of a merger and who knew what when.

Plus it has been clear for a long time that all has not been well with Jobs, something any investor had to be aware of.

I have no inside information; nor have I talked to anyone who has treated him, but anyone who has not been on Mars for the past year could see that Jobs was not looking great, especially from his woefully haggard appearance.

As I have written:

Apple investors who have not figured Jobs’s precarious health–after a round with any kind of cancer–into their investment strategies about Apple going forward need some serious reality medication themselves.

Guess what? Jobs has been really sick and it means he is going to have a harder time with any kind of infection or complication for the rest of his life, and he will likely be more delicate than someone who has not had cancer.”

Who knows if the government will find out more, but it would be good if some of the smoke could be cleared away to see if there is some actual fire or not.

And if not, Jobs can get the peace he is seeking to try to recover his health.

As he said to Bloomberg last week: “Why don’t you guys leave me alone–why is this important?”

It would be nice to be get that answer and then, hopefully, let Jobs get on with getting well.