NEW YORK — At the very least, ABC News’ Brian Ross figured he’d find a White House official, prominent lobbyist or a congressman when he was handed a stack of phone records from a Washington, D.C. escort agency.Yet there wasn’t much there. Ross’ “20/20” report earlier this month on Deborah Jeane Palfrey, the woman accused of running a prostitution ring catering to the capital’s elite, instead felt like one of those encounters you regret in the morning.

Such are the risks of investigative journalism, where every promising path is as likely to end in a dead end as it is a gold mine.

While Palfrey turned the records over to Ross to save her hide, of course, she was also paying a compliment. Ross, 58, has established himself as television’s most visible serious investigative journalist, leading a 15-member team with its own web page, “The Blotter,” on abcnews.com and frequent reports across all of ABC’s broadcasts.

Ross won a Peabody Award for breaking the congressional page scandal story last fall. He earned a George Polk Award in 2005 for reporting on secret CIA prisons in eastern Europe. His team has reported frequently on terrorism threats and the impact of campaign donations on the political process.

“His reputation in the industry is excellent,” said Brant Houston, executive director of Investigative Reporters and Editors, Inc. and a professor at the University of Missouri School of Journalism. “He is leading the way in terms of mainstream journalism in how to use the blog effectively. It’s great to see that kind of reporting.”

Ross’ team serves in effect as an in-house news service within ABC News. He pitches stories to “World News,” “Nightline,” “Good Morning America” and the newsmagazines. Some that aren’t broadcast make their way onto “The Blotter,” which has received 36 million hits in a year.

Rhonda Schwartz and Chris Isham are his top producers, leading a team of specialists in areas like campaign finance, law enforcement and terrorism.

Ross joined ABC News from NBC in 1994. It was after the 2001 terrorist attacks that the network centralised and built up its investigative operation under him.

It’s an area of broadcast journalism — print, too — that is frequently the first place that news executives look at when cutting budgets. ABC News President David Westin said that didn’t make sense to him.

“At a time like this, we need to make sure we take the resources we have and put them into things that others aren’t doing, not in simply trying to replicate something that others are doing and try to do it a little better,” he said.

NBC News has a similar investigative unit led by Lisa Myers, with a staff about half the size of Ross’. CBS News recently appointed Armen Keteyian to do investigative pieces, and will announce today that former ABC producer Keith Summa has been hired to run the investigative unit. Although he’s enthusiastic about Keteyian’s work,

“CBS Evening News” executive producer Rick Kaplan said, “right now the gold standard for this is Brian.”

The terrorist attacks have led the networks, in general, to pay more attention to this sort of reporting than they did a decade ago, said news consultant Andrew Tyndall.

Ross said his unit is so busy in part because he feels the need to justify ABC’s commitment. His visibility — 74 reports last year on “World News” alone — runs counter to the image of investigative reporters as shadowy figures seldom heard from.

“If they start to think of you as very expensive and only occasionally showing up and kind of weird, that doesn’t work,” he said.

Moving quickly and frequently to the air has its risks, increasing the chance of reliance on sources who are wrong. Ross reported in 2001 that Saddam Hussein was suspected of being behind anthrax attacks. That turned out not to be the case — a theory government investigators were following turned up dry — but it won Ross a persistent, sceptical critic in Salon blogger Glenn Greenwald.

The US Customs Service was also angered when Ross’ team smuggled depleted uranium into New York to test how authorities are guarding against the possibility of a “dirty bomb” attack, saying they had to waste time dealing with a fake threat.

“I’m comfortable challenging people in power, if that’s what we have to do to challenge their assertions,” he said. “I wish to heck we had done a story about airport security in June of 2001.”

When the D.C. Madam brought her phone records to Ross, the investigative unit set about tracing the numbers. They came up with about 30 names that might be of interest, and Ross began calling many of them. Randall Tobias, head of the Bush administration’s foreign aid programmes, resigned the day after Ross called him, although he said there had been no sex when the escorts visited his condo.

The only other customer’s name to surface in the investigation was Harlan K. Ullman, a military strategist, whose name was released by Palfrey in April.

Ross found the phone list contained the names of corporate leaders, Pentagon and NASA officials. One customer’s lawyer tried to offer Ross a deal: “What story could I give you that would be more interesting than the story about my client?”

Ross turned him down flatly.

Ultimately, the client’s name wasn’t used. Ross and ABC lawyers agreed that while the jobs of some alleged customers were interesting, their names would mean nothing to most people. So they decided not to release them.