A Planned Parenthood office is seen in New York City. (Andrew Burton/Getty Images)

A special House committee formed amid the debate over Planned Parenthood’s handling of fetal tissue has launched a broad investigation into the matter, requesting documents from more than 30 agencies and organizations, including some of the nation’s most prominent research institutions.

Critics have raised concerns about the breadth of the ­Republican-led inquiry and are worried about the privacy implications of the wide-ranging requests.

The investigation is moving ahead quickly despite recent legal setbacks for the Center for Medical Progress, the antiabortion group that produced the undercover videos that sparked the inquiry. Two of the people involved in producing the videos were indicted by a Texas grand jury last month, and earlier this month a federal judge in California issued a second restraining order preventing CMP from publicly releasing more of its work.

But Rep. Marsha Blackburn (R-Tenn.), chairman of the House panel, said in an interview last week that the questions the videos raise persist.

“You have these precious children that are aborted and then these parts are being sold,” she said. “People want to give this a good and thorough look.”

She announced Thursday that the panel would issue subpoenas to three organizations that “failed to fully cooperate with document requests.” The burst of activity made it clear that the panel, which emerged from last year’s turmoil inside the House GOP, is not planning to shy away from some of the country’s most polarizing issues in a presidential election year.

The subpoenas went to Stem­Express, a California firm that prepares human specimens for researchers; Southwestern Women’s Options, an Albuquerque abortion clinic; and the University of New Mexico, whose Health Sciences Center conducts medical research using fetal tissue.

In a letter Friday, the panel’s Democrats sharply objected to the subpoenas, calling them “abusive and unjustifiable.” The requests have generally sought materials across more than a dozen categories, according to people who have reviewed the letters.

The University of New Mexico released its correspondence with the panel Friday. The initial request, dated Jan. 6, sought a wide range of records in 19 categories, including a list of entities with which the university has exchanged fetal tissue; an organizational chart listing all personnel dealing with that tissue; laboratory equipment records; assorted banking, accounting and tax records; copies of various university policies and guidelines; and communications with local, state and federal officials.

In a subsequent email, a staff member requested the names of all employees and students “who perform or assist in performing abortions or conducting fetal tissue research,” prompting objections from the university’s attorneys.

The panel’s ranking Democrat, Rep. Jan Schakowsky of Illinois, said she was concerned that the names of researchers or clerical employees could be leaked or inadvertently released, making them targets for antiabortion extremists. “I’m not suggesting that they want to put these people at risk,” she said, “but they could be made to be at risk.”

The university said in a statement that it was “disappointed” by the subpoena and that it was cooperating with the requests and would provide additional records next week in accordance with an extension previously negotiated with the panel’s staff.

Blackburn on Friday defended the breadth of the document requests and said the names are necessary to develop a “complete picture” of the fetal tissue trade. “I think they fully understand what we are seeking,” she said. “If they’re not going to work with us, we’re going to have to come at this a different way.”

The identities of the organizations that have been contacted have been closely held. Republicans say they want to protect the integrity of their investigation; Democrats and the institutions say they fear undue public scrutiny if the requests are publicized.

About half of the requests have gone to academic institutions or research hospitals, people familiar with the panel say. The rest have gone to clinics and “procurement entities,” many of which are targets of antiabortion activists. Southwestern Women’s Options, for instance, is one of a handful of U.S. clinics that perform late-term abortions, while StemExpress was featured in some of the Center for Medical Progress’s videos.

StemExpress said in a statement that it has turned “numerous materials” over to the House panel as well as to other congressional committees that opened investigations in response to the videos. “Throughout this process, StemExpress has continued to protect its clients’ confidentiality, and to abide by its legal obligations,” the company said. “The Select Investigative Panel now seeks confidential client information and the identity of individual scientists and researchers through the issuance of a subpoena.”

Southwestern Women’s Options said in a statement that it has cooperated with investigators and delivered documents Friday. “We will continue to be responsive to the panel’s inquiries and will do so in a manner that protects individuals’ safety and privacy,” it said.

The special committee was proposed in September, as then-House Speaker John A. Boehner (R-Ohio) sought to tamp down a growing revolt from conservative Republicans. After the videos’ summer release, GOP lawmakers pressed to strip federal health-care funding from Planned Parenthood, whose affiliates perform about one-third of the nation’s abortions. With President Obama and congressional Democrats firmly opposed, such a move was likely to cause a government shutdown, which Boehner was determined to avoid.

The revolt ultimately forced Boehner to resign, but plans proceeded for the panel, frequently called the “Select Committee on Planned Parenthood” by Republicans and Democrats alike. On a party-line House vote, it was given broad authority to investigate fetal tissue procurement and U.S. abortion practices in general.

One group that has not been subject to the panel’s inquiries is Planned Parenthood. But Blackburn did not rule out that a request might be forthcoming, and Schakowsky said she expected one.

“They have an agenda, which is to discredit this kind of activity,” Schakowsky said. “They want to find something that documents what they’ve already concluded — that fetal tissue research, that the whole process involved with that is illegitimate in some way.”

David Daleiden, the activist behind the Center for Medical Progress videos who is now facing a felony fake-ID charge in Texas, said in a recent interview that “the documents will tell the story” of how fetal tissue moves from abortion providers such as Planned Parenthood to intermediaries such as Stem­Express to researchers.

“I think that committee has a lot of tools at its disposal that no investigative journalist, no matter how good, has access to,” he said.

The financial and accounting records the panel has requested could be used to examine whether any of the entities violated a 1993 federal law banning the transfer of human fetal tissue “for valuable consideration.”

Planned Parenthood has said it has been paid only reimbursements for the overhead involved in the preparation and transportation of tissue donations. A dozen states have investigated those claims and found no wrongdoing.

Although Blackburn said it is unlikely that the panel will make any report before the presidential election in November, its work is certain to continue to be suffused with politics. That has been made plain in the names Republicans and Democrats are using to describe it. For the former, it is a select investigative panel to “protect infant lives”; for the latter, it is to “attack women’s health.”

Blackburn said that after months in the shadows, the panel’s work will soon go public. Its first hearing is set for early March; the subject and the witnesses who will be invited have not been determined. “This is focused on infant lives, and we are going to go at it,” she said.

Schakowsky said Democrats will soon issue their own document requests, with an eye toward illuminating the benefits of the medical research in question. “We’re more than willing to have a two-sided discussion about fetal tissue and scientific research,” she said.

Sandhya Somashekhar contributed to this report.