Authorities in the southern Chinese province of Guangdong have issued a summons to two sisters of rights activist Zhang Liumao after they spoke out over strong evidence that he was beaten to death in police custody. Zhang Wuzhou and Zhang Weichu were issued with the summons in a telephone call from police in the provincial capital Guangzhou on Tuesday. "I got a call from the Shijin police station today, summoning me and my sister for questioning on suspicion of 'picking quarrels and stirring up trouble,'" Zhang Wuzhou told RFA. "They accused me of hitting a police officer and they accused my sister of smashing their trash can," she said. Zhang Liumao was reported dead by authorities in the police-run Guangzhou No. 3 Detention Center in the early hours of Nov. 4, prompting suspicions from his family that he was tortured. Zhang Wuzhou said the sisters had reacted in an angry outburst during a visit to the police station on Nov. 6 after receiving no answers to their questions on the sudden death in custody of their brother. The summons likely related to scuffles that broke out at the time, she said. "We lost our cool, and I think my sister vented her frustration on the trash can, and a police officer came over to grab her, and I rushed and stood in between them," Zhang Wuzhou said. "They said I hit him; I am not sure if I did or not, but I was[scolding him] and jabbing my finger at him, and now they're saying I hit him," she said. "They kept lying to us that day, repeatedly, and we were so sick of waiting," she said, but added that she believes the charges are a form of retaliation after the family spoke to the media about Zhang Liumao's death. "I think they are afraid that we will expose the truth, and that's why they want to detain us," Zhang Wuzhou said. "We plan to get ourselves a lawyer because they are just bullies trying to threaten us." Since she spoke out about her suspicions surrounding her brother's death, Zhang Weichu has already lost her job, Zhang Wuzhou added. The summons comes just days after Zhang Liumao's lawyer viewed his body, saying it showed multiple signs of severe physical assault. China's record on torture Chinese officials questioned at the United Nations, which last week reviewed Beijing's record on torture, said they were doing all they can to put safeguards in place amid reports that the use of torture, cruel and degrading treatment is endemic under Communist Party rule. Lawyer Tan Chenshou told RFA after the identification process that there was bruising visible all over Zhang Liumao's body, including his chest and abdomen, adding that a swollen area on his client's arm suggested a bone had been broken. Guangdong-based rights lawyer Chen Jinxue said on Tuesday he has already accepted instructions to act for the sisters in their case. "So far, the police station has only made a phone call to Zhang Wuzhou to tell them to go to the police station, but there has been no formal summons issued," Chen said. "I think they are just trying to frighten the family," he said. The United Nations Committee against Torture last week reviewed China's compliance with the Convention against Torture and Other Cruel, Inhuman or Degrading Treatment amid widespread criticism of Beijing's record from U.S. politicians and rights groups. According to the Congressional Executive Committee on China (CECC), and the New York-based groups Human Rights Watch and Human Rights in China, torture is widespread across China's judicial system, and Beijing's attempts to change the practice are merely cosmetic. Activists said that a number of rights lawyers, activists and former victims of torture had been prevented from traveling to give evidence to the committee in Geneva by the Chinese authorities in recent weeks. Chinese ambassador Wu Hailong told the 10 independent experts in Geneva on Tuesday that Beijing is "working to eliminate torture" by improving the training of police and prison guards, and audio and video recordings of interrogations. But rights activists said China traditionally relies heavily on evidence from forced confessions across its judicial system, sometimes using it as the only evidence or the main evidence. The CECC said it has gathered reports that torture and other human rights abuses "continue to be routine" in China, and include the denial of medical treatment and the use of forced hospitalization in psychiatric facilities. The widespread use of unofficial detention centers, known as "black jails" and a lack of clear definition of torture in law ensures the practice goes unpunished, it said.