Editor's note: This story has been updated.

A Texas-based Planned Parenthood affiliate on Thursday moved to join a federal lawsuit filed in California against the anti-abortion group behind undercover videos of the organization’s clinics.

The lawsuit, filed in a San Francisco-based federal court in January, alleges the Center for Medical Progress engaged in conspiracy, fraud and other activities that violate organized crime law and other federal regulations in its pursuit of secretly recorded videos of Planned Parenthood. Citing recordings of staff at a Houston clinic, Planned Parenthood Gulf Coast filed to join the lawsuit as a plaintiff.

The recordings, released by the group last summer, depicted Planned Parenthood staff discussing the procurement of fetal tissue. The group alleged that Planned Parenthood was illegally profiting from the sale of tissue of aborted fetuses — an accusation the organization has vehemently denied.

The lawsuit against the group was first filed by Planned Parenthood Federation of America and seven California affiliates against the Center for Medical Progress, Biomax Procurement Services and several anti-abortion activists, including videographers David Daleiden and Sandra Susan Merritt.

A request for comment from the Center for Medical Progress was not immediately returned.

Daleiden and Merritt were previously indicted on criminal charges in Harris County. The indictments included charges against Daleiden and Merritt for tampering with a governmental record. The two activists allegedly used fake California driver’s licenses while visiting a Planned Parenthood Gulf Coast clinic last year.

In light of those charges, the Center for Medical Progress has since claimed its “citizen journalists” were working under First Amendment protections.

The alleged use of the falsified driver’s licenses was first reported in July when Planned Parenthood Gulf Coast confirmed to The Texas Tribune that two people “fraudulently representing themselves” as research executives toured a Planned Parenthood facility in April “under the guise of discussing tissue research with our clinic research staff.” The two individuals identified themselves as executives with Biomax Procurement Services, a shell company created by the Center for Medical Progress, a Planned Parenthood spokeswoman said.

Posing as research executives under different names, Daleiden and Merritt also signed strict nondisclosure agreements to enter a Houston clinic and speak to staff about "internal operations," the lawsuit claims, and the videographers violated the agreements in August when they posted secret recordings of Houston staff.

Planned Parenthood Gulf Coast’s move to join the lawsuit is the latest development in a flare-up that followed the release of the undercover videos.

The sale of fetal tissue is illegal. But if a patient consents, abortion clinics may donate fetal tissue for use in medical research. Federal law allows clinics to be reimbursed for costs “associated with the transportation, implantation, processing, preservation, quality control, or storage of human fetal tissue” for research purposes.

Planned Parenthood health centers in Texas do not currently donate tissue for medical research, their officials say, and Planned Parenthood Gulf Coast in Houston hasn't done so since 2010, when it partnered with the University of Texas Medical Branch at Galveston for a study on causes of miscarriages.

But with allegations flying that Planned Parenthood was breaking the law, state leaders quickly pressed for state and local investigations and called for curtailing the organization’s participation in government-funded programs. Those efforts have produced few results, but they led to the indictment of the two anti-abortion activists.

Disclosure: Planned Parenthood was a corporate sponsor of The Texas Tribune in 2011. A complete list of Tribune donors and sponsors can be viewed here.