Some of the lawyers in the field, including several from Mr. Phillips’s firm, played a central role in advising the Securities and Exchange Commission on the rules creating its whistle-blower program, including a provision to broaden the list of who was eligible to file a claim. In the last year, law firms that represent whistle-blowers have hired several top S.E.C. officials who helped write those rules. They include Jordan Thomas, who has started a new S.E.C. whistle-blower unit at Labaton Sucharow, a New York firm whose employees have contributed to the Obama campaign.

“We have had hundreds and hundreds of inquiries,” said Mr. Thomas, who has sought out clients and promoted his firm’s practice in speeches nationwide, an Internet blog and YouTube videos. “Our phones are ringing off the hook.”

The push to crack down on Medicare fraud, for example, started long before the Obama administration, with many cases initiated by the Justice Department under President George W. Bush. But the Obama administration has been particularly aggressive in pursuing them.

Since January 2009, $13.2 billion has been collected by the federal government from companies through the False Claims Act, the primary whistle-blower tool, with about $9.4 billion of that involving alleged health care fraud. The federal government has recovered more in financial penalties against drugmakers since 2009 than in the previous 18 years combined, with whistle-blowers credited for helping initiate about three quarters of the cases, according to a recent study by Public Citizen, a nonprofit group.

Among the biggest False Claims Act settlements was a $2 billion fine against GlaxoSmithKline, accused of illegally promoting one of its blockbuster drugs, which could translate into a more than $100 million bounty for the whistle-blowers, two of whom were represented by Mr. Phillip’s firm. In May, Abbott Laboratories agreed to pay an $800 million fine, which included an $84 million payment to the whistle-blowers, four former Abbott sales staff members, who tipped off authorities about illegal marketing of an antiseizure drug to children and elderly patients. The lead whistle-blower was represented by Grant & Eisenhofer, a Delaware-based firm whose managing director has also served as bundler and contributor to Mr. Obama.

The S.E.C. whistle-blower program targets fraud that harms investors or consumers through a securities law violation, while the health care cases typically involve cheating the Medicare or Medicaid programs. No big fines have resulted yet from the S.E.C. program because cases typically take several years to develop. But the office is receiving on average 10 tips a day, and got nearly 3,000 in its first year.