Two anti-abortion activists who secretly recorded conversations with Planned Parenthood have each been charged with 15 felonies in California.
David Daleiden and Sandra Merritt filmed undercover videos of themselves trying to buy foetal tissue, California Attorney General Xavier Becerra said.
The pair created a fictitious bio-research firm and used fake identities for meetings with the healthcare group.
Prosecutors say their actions invaded people’s privacy.
“The right to privacy is a cornerstone of California’s constitution, and a right that is foundational in a free democratic society,” Mr Becerra said.
“We will not tolerate the criminal recording of confidential conversations.”
Planned Parenthood is a non-profit group that provides reproductive health services to mostly lower-income Americans. Some of its clinics perform abortions.
According to the charges, Mr Daleiden and Ms Merritt engineered meetings with staff from Planned Parenthood and StemExpress, a California company that provides blood and tissue for medical research.
They allegedly taped people without consent 14 times between October 2013 and July 2015.
The pair face a charge for each individual secretly recorded, and a further count of criminal conspiracy to invade privacy.
Mr Daleiden and Ms Merritt have already faced similar charges in Texas, which were ultimately dropped.
In an email to The Associated Press, Mr Daleiden called the charges against him “bogus” and said they were coming from “Planned Parenthood’s political cronies”.
Mr Daleiden’s lawyer, Steve Cooley, said his client is “a martyr who’s being crushed by the power of the State of California”.
The Center for Medical Progress – the activists’ anti-abortion group – caused a political uproar in 2015 when its heavily-edited videos accused Planned Parenthood of illegally selling aborted foetuses for a profit.
Planned Parenthood denied that, saying it is allowed to donate tissue to research firms for a procurement fee.
Human foetal tissue has been used in research since the 1930s, with current work focusing on diseases like AIDS and Parkinson’s.
More than a dozen states investigated the profit claims, but found no evidence of illegal tissue harvesting or sales.
Last month, a judge in Texas blocked attempts to cut government funding to Planned Parenthood over the secret videos, saying the state had failed to provide evidence of wrongdoing.
“A secretly recorded video, fake names, a grand jury indictment, congressional investigations – these are the building blocks of a best-selling novel,” the judge declared.
Planned Parenthood said this week: “As we have said from the beginning, and as more than a dozen different state investigations have made clear: Planned Parenthood has done nothing wrong, and the only people who broke the law are those behind the fraudulent tapes.”