Beijing police have quashed rumors the rape allegation made against the son of a famous PLA singer has been dropped.

Li Guanfeng, previously named Li Tianyi, was detained along with four other males on Feb 20 on suspicion of sexual assault.

The 17-year-old is the second child of army singer Li Shuangjiang and his wife Meng Ge.

Beijing Morning Post reported on Tuesday that a post shared on micro-blogging platform Sina Weibo suggested the victim had withdrawn the allegation.

However, a police spokesman told the paper the rumor was untrue and the case is still being investigated.

Criminal attorney Qi Lianfeng also confirmed that Chinese law does not permit the victim to drop the charge.

"It is a criminal case," he was quoted as saying. "Prosecutors will take on the case only if the police investigation finds evidence against the suspects."

An officer with Haidian district police who declined to give his name told China Daily on Sunday that the five suspects are accused of gang raping a woman in a hotel room on Feb 17 after a night of drinking.

Meanwhile, netizens have questioned whether Li Guanfeng is really aged 17, citing a video interview with his father recorded by Sina in 2006.

In the footage, the PLA singer says his son (at the time named Li Tianyi) is 14, which would make him 22 or 23 today, and would allow prosecutors to try him as an adult if police charge him with rape.

Beijing police have not yet responded to the question concerning his age.