When Chen Ying fired her way to glory in the women's 25m pistol shooting event on Wednesday, she had no idea her family was keeping a huge secret from her.

Chen's mother, 56-year-old Zhang Zhimin, has breast cancer.

Over the past two months, Zhang has been to hospital four times for chemotherapy sessions. Each time, she kept her visits secret from her daughter.

"My girl won the gold medal. It was worth suffering the pain alone for all that time," Zhang told China Daily Thursday in Beijing.

Chen Ying's parents (left) accept a bouquet of flowers from neighbors congratulating them on their daughter's success August 14 2008. [Xinhua]

"I just wanted her to be able to concentrate 100 percent on her shooting. I know how hard she has trained for the Olympics over the past four years," she said.

After collecting her gold medal on Wednesday, Chen received a phone call from her mother, telling her what had been going on.

"It was really hard for me to admit that I had lied to her, even over the phone," Zhang said.

"But even when I had spoken to her before, I was always scared she might be able to notice the changes in my voice after I had the chemotherapy," she said.

Chen's father, Chen Cungui, said he was worried how his daughter might react when she heard the news, as she is a very sensitive girl.

"Chen Ying burst into tears when she found out over the phone what her mother had done for her," he told China Daily Thursday.

Qin Zhang, Chen's coach before she joined the national shooting team, said: "It was very hard for Chen's mother to lie to her daughter, but it was a white lie.

"I know she spent a long time wrestling with her own feelings about whether to say anything or not," he said.

"Once, when she was in a lot of pain after a chemotherapy session, Zhang begged me to call Chen and tell her everything.

"But then she calmed down and told me not to. She never wanted to upset her daughter," Qin said.

"Chen Ying called me Thursday and asked if I would make some nice food for her mother, as she won't be able to until after the Olympics," he said.

Zhang said she hates having to endure the chemotherapy sessions, but knows that she has to go through it if she is to succeed in her fight with breast cancer.

"I'm really fed up with the pain the treatment causes me, but I know my next session will be a lot easier," she said.

"Because I will have my daughter there to hold my hand."