The US House Foreign Affairs Committee has endorsed a resolution calling on China to end what it calls state-sanctioned harvesting of human organs from prisoners, it has been reported.
China accused the panel of making "false and irresponsible accusations".
Human rights groups have long criticised China for taking organs from executed prisoners as the source of most transplanted organs.
In 2012, China announced plans to abolish the practice in three to five years, according to the South China Morning Post.
The resolution, which now goes to the full House, states there are "persistent and credible reports" of state-sanctioned organ harvesting from non-consenting prisoners.
The reported include large numbers of organs from the Falun Gong meditation movement, a Chinese spiritual discipline supressed in the nation, and members of other religious and ethnic minority groups.
Falun Gong was banned in China in 1999, calling it a "heretical organisation" that threatened social stability. The Communist Party leadership initiated a nationwide crackdown and multifaceted propaganda campaign intended to eradicate the practice.
The resolution, announced on Wednesday, also calls for a State Department investigation into transplant practices in China.
The resolution's chief sponsor, Republican Rep. Ileana Ros-Lehtinen, accused China's government of a "violent and targeted campaign" against Falun Gong practitioners and claimed detainees are executed for their organs.
Rep. Eliot Engel, the committee's leading Democrat, called organ harvesting an "unconscionable violation of human rights".
He said the targeting of people for their faith or ethnicity intolerable and that there was no indication China is living up to its word to end transplants from executed prisoners and set up a voluntary organ donation system.
Chinese Embassy spokesman Geng Shuang said that Chinese regulations required every organ transplant to have the consent of the donor in written form.
"The so-called organ harvesting from death-row prisoners is totally a lie fabricated by Falun Gong," Geng said by e-mail, as reported by the New Zealand Herald.