Abortionists and tissue resellers toyed with fetal organs before selling them off, according to a former procurement official.

Holly O’Donnell, 24, told the nonprofit Center for Medical Progress that she once witnessed a doctor stop and start a beating heart with medical instruments. The official is alleged to have said, "I want to see something kind of cool" as the heart twitched.

"She just taps the heart, and it starts beating. And I’m sitting here and I’m looking at this fetus, and its heart is beating, and I don’t know what to think," O’Donnell said.

O’Donnell worked for StemExpress, a company that partnered with Planned Parenthood in California to harvest and sell organs obtained via abortions to medical researchers. The company pioneered techniques used to maintain heartbeats from aborted babies to better preserve them. One of the main slogans on the "About Us" section of its website is "the purity, viability, and quality you need."

"StemExpress has been cited in published scientific literature as a source of fetal hearts used for Langendorff perfusion, which keeps a heart beating after it is excised from the body," a CMP press release said.

StemExpress denied the accusations made by its former employee.

"We have never requested or received an intact fetus. StemExpress performs extensive work to test, isolate and purify the donated cells so that researchers can use them to help find cures and treatments for life’s significant medical conditions," the company said in a statement.

The company released a statement on Saturday claiming to have cut ties with the country’s largest abortionist.

"Due to the increased questions that have arisen over the past few weeks, we feel it prudent to terminate activities with Planned Parenthood," it said.

CMP has previously released documentary videos featuring Planned Parenthood officials discussing the sale of organs and the best way to "line item" babies to maximize the price. Officials were also captured candidly talking about the ways they can change abortion procedures to ensure that parts come out "intact."

Federal law prohibits altering abortion methods for organ harvesting, as well as profiting from the practice.

O’Donnell, who quit the company and is now pro-life, described cutting into the face of a baby who was the victim of a late-term abortion at the insistence of a supervisor. The procedure is used to extract the brain.

"Since the fetus was also intact, she [her supervisor] said ‘okay well this is a really good fetus. It looks like we’re going to procure a lot from it," O’Donnell recalled, as she teared up. "That was the moment I couldn’t work for the company anymore. … I didn’t want to be that person."

CMP’s videos have made waves in Washington and in the 2016 presidential race. Nearly every Republican has condemned Planned Parenthood and organ harvesting. The Democratic frontrunner Hillary Clinton, the top recipient of Planned Parenthood employee contributions, called the videos "disturbing" before backtracking and criticizing pro-life activists and candidates.

Senate Democrats blocked legislation that would have reallocated the $500 million Planned Parenthood receives from taxpayers to local women’s health clinics.

Planned Parenthood, which did not return a request for comment, has denied any wrongdoing and is now the subject of investigation by Congress and more than half a dozen states.

UPDATE 5:25 P.M.: This post has been updated with comment from StemExpress.