Planned Parenthood recently tried to defend itself from charges that it illegally harvests and sells aborted baby parts but apparently ended up incriminating itself.

In an 11-page letter sent to Congress explaining the organisation's practices, Planned Parenthood president Cecile Richards admitted accepting payments ranging from $45 to $60 "per tissue specimen" from aborted babies, but said these were reimbursements to cover costs, which federal law allows.

Planned Parenthood remains under heavy attack, particularly from members of the Republican Party and anti-abortion groups, following the series of sting videos released by the Center for Medical Progress (CMP), some of which showed Planned Parenthood officials and their partners discussing and even joking about the sale of foetal parts.

In the letter, Richards noted that "adjustments that facilitate foetal tissue donations rarely occur at our few clinics that offer women this service," according to the Washington Times.

Richards' statement, according to CMP's David Daleiden, only proved and supported the findings of their investigation—that foetal parts are sold based from the "adjustments" in prices.

In the eight videos released so far by CMP, Planned Parenthood officials are heard haggling over prices of foetal parts with undercover agents pretending to be biotech firm purchases. In one case, a Planned Parenthood official even joked that she wanted a "Lamborghini" (a brand of an expensive luxury vehicle) apparently as payment for the aborted baby parts she would be selling.

"Both of these admissions speak to Planned Parenthood's financial benefit and profit motive for supplying foetal tissue, and both are the points CMP's videos have documented and illustrated from the very beginning," Daleiden said in a statement.

He said the admitted $45 to $60 per specimen payment was charged only to cover costs, and that tissue-procurement organisations "handle all dissection, packaging and shipping of foetal organs" while Planned Parenthood spends "10 minutes consenting a patient."

"And when a Planned Parenthood doctor manipulates the abortion to get higher-quality baby parts, they are prizing Planned Parenthood's financial interests ahead of women's health," he said.

In the letter, Richard wrote: "I am writing today because we are doing as much as we can to collect the facts and share them with you. We are also cooperating with the House and Senate committees that have requested relevant information from us."

She condemned the undercover videos released by CMP for being subjected to "selective editing," "splices," distortions" and other forms of "manipulation."

"This review ultimately concluded that the manipulation of the videos and the transcripts means they have no evidentiary value in a legal context and cannot be relied upon for any official inquiries unless supplemented by the original video in unaltered form," she said, adding that CMP lacks "any credible evidence that Planned Parenthood has done anything wrong."