Chinese police officers raided the office of a prominent non-governmental organisation in Beijing this week, seizing laptops and details of contacts, its co-founder said on Thursday, the latest target of China's crackdown on dissent. Lu Jun, co-founder of Yirenping, an anti-discrimination NGO, said about 20 police officers broke into its offices in the early hours of Tuesday, taking away financial receipts, project contacts and several computers and laptops. Chinese President Xi Jinping has overseen a broad crackdown on the country's rights community since he took office in 2013, in what some groups call the worst suppression of dissent in two decades. Lu said before the search, police had taken his colleague, a man surnamed Cao, into custody for several hours and entered the office with Cao. Cao had been involved in a project on public interest law and has since fled Beijing, according to Lu. Lu said he believed the raid was linked to his calls for the release of five women activists, who were detained just over two weeks ago, apparently for planning to demonstrate against sexual harassment on public transport. "I feel the message is that the police want to suppress my calls for solidarity with these women rights activists," Lu said in a telephone interview from New York, where he is a visiting scholar. "The second signal is that striking down NGOs is a priority." A police officer in the Yangfangdian district, which administers the area where Yirenping is located, was unable to comment when asked to confirm the raid. "Authorities have become increasingly concerned with foreign funding," Maya Wang of New York-based Human Rights Watch said in emailed comment to Reuters, pointing to the passages devoted to foreign funding in a slew of new security laws. Police have denied medication to Wu Rongrong, one of the detained women activists suffering from a chronic liver disease, after determining that she does not need it, said her lawyer, Wang Fei. "Before, she was detained, she was always taking the medication for anti-viral treatment," Wang said. "From what I've seen, her physical condition is poor and her face looks jaundiced." The Haidian detention centre, where Wu is being held, declined to comment. Foreign NGOs in China have told Reuters they are bracing for a crackdown as the government prepares to pass a new law to regulate their activities.