Fan Li Lingxiao wrote online: "I have been your fan since you released your first song. Drugs offer no help to life's crises. They only mislead you. I hope you can come back one day and sing for the fans."

In 1994, Chen, a Beijing native, dropped out of school and started his career as a singer-songwriter. The same year, Hu Haiquan, who started composing at age 11, came to Beijing from Northeast China and played keyboard for bands around the city.

Two years later, the two met for the first time, and Chen came up with the idea to form a band. Taking one syllable from each of their names, they became Yu Quan in 1998.

In 1999, their debut album, The Most Beautiful, propelled the pair to success. With 11 original studio albums released over the last 20 years, which have sold about 10 million copies in total, Yu Quan has become one of the most-popular duos in the country.

The pair also opened restaurants in Beijing and Shanghai. Just three days before Chen was arrested, the duo's new restaurant opened in Beijing's China World Trade Center Tower 3.

According to Xinhua News Agency, the Beijing Trade Association for Performances said on Sept 8 that Chinese stars who have been involved in drug abuse, gambling or consorting with prostitutes will be banned from any public performances. The association also signed a joint letter, promising that they will neither hire nor host stars who have been involved with drugs, gambling and prostitution to participate in performances. Over 200 members of the association have signed the letter in order to "purify the capital's performance market".

"It gives the wrong message to the general public, especially young people. The association holds the responsibility to keep the industry on a healthy course and promote performers' social duties," says Zhang Haijun, president of the association.

The past few years have seen a string of high-profile arrests of Chinese celebrities for alleged drug abuse. In 2014, Jaycee Chan, the son of Hong Kong movie star Jackie Chan, was caught and convicted of drug offenses.