A swimming coach in Chongqing may face criminal charges after forcing a girl into the water during a lesson at a sports club on Friday, after which she nearly drowned.

The 7-year-old girl was pronounced brain dead on Saturday.

A man who witnessed the event told China Daily that he saw a woman in a black swimming suit dragging the girl into the pool at the HP Fitness Club in Yubei district on Friday afternoon.

The girl did not have any buoyancy aids, and struggled in the water for a few minutes before drowning, said the eyewitness, who wished to be identified only by his surname, Ma.

The girl was then spotted by a male lifeguard, who pulled her from the water and attempted to resuscitate her, said Ma.

Describing the woman who dragged the girl into the water, Ma said that he thought she was a "tiger mother", meaning a mother who pushes her child to succeed, and this is why he did not intervene.

The girl's mother, surnamed Wang, was too grief-stricken to talk to China Daily on Monday.

According to Chongqing Morning Post, Wang said on Saturday that she was not allowed to enter the pool during her daughter's lesson because she was wearing a dress on that day, and only people wearing swimming suits were allowed into the pool area.

The mother then waited in the lobby downstairs until someone informed her that her daughter had drowned.

The girl was sent to the Children's Hospital of Chongqing Medical University. A spokeswoman for the hospital said the girl was almost dead when she arrived.

"Her pulse was very weak and her heart had almost stopped. ... Although she has a weak heart beat now, she has been confirmed brain dead, and the chance of survival is low," said the spokeswoman, who would not be named.

Chongqing police said they have filed the case for investigation, but would not give further details, such as whether the swimming coach was properly licensed.

Li Yang, the club's manager on duty on Monday, confirmed that a customer drowned in the club last week but said that he didn't know much about the incident because he was not in charge of the case.

However, he said that the swimming coach involved in the case had been suspended.

The club was still open for business on Monday.

Yi Shenghua, a Beijing-based lawyer, said the coach and the club both have criminal liability.

He said if the girl dies, the coach could be charged with manslaughter through negligence or indirect intentional homicide, depending on the details of the case. If convicted, the coach may face more than 10 years in jail.

"Many coaches use very strict training methods, and may cause the deaths of their students. Kids don't know how to swim and it is dangerous to force them into the pool," he said, adding that the club is also liable for compensation.

Some senior coaches questioned the current standards used for issuing certificates to swimming coaches.

According to one senior swimming coach from Chongqing: "The only requirement for hiring swimming coaches in many clubs is the swimming coach certificate. However, it is far too easy to gain the certificate nowadays." The coach, who has 40 years of experience declined to give his full name for fear of reprisals from local sports clubs.

"A person who knows how to swim, gets trained for three to five days and pays some money can easily get the certificate," he said, adding that the coaching certificate is provided by the local swimming association.

"Many coaches don't know how to teach," he said, adding it is the responsibility of coaches to watch the students, understand the children's reaction to the water and help them get used to the pool.

"It is so unprofessional to let a child drown," he said.