Family planning authorities confirmed on Monday that film director Zhang Yimou fathered three children out of wedlock, ending months of speculation that he had fathered as many as seven children by various mothers.

Zhang admitted to having three children with his cur-rent wife Chen Ting, and he apologized on Sunday evening in a statement posted on his studio's micro blog.

The apology came amid growing concerns about whether celebrities like Zhang can dodge the punishments of family planning laws.

The family planning authority in Binhu district of Wuxi, Jiangsu province, which is the hometown of Zhang's wife, announced on Monday evening that Zhang fathered three children — in 2001, 2004 and 2006 — with his current wife before their marriage in 2011.

The authority said it welcomed the response from Zhang's studio, as well as Zhang's cooperative attitude toward the investigation.

"We hope that the party involved will continue to cooperate with the investigation and accurately declare his income in the birth year of each child. We will handle the case according to the law and in time will announce the result," an official with the family planning bureau in Binhu district said in an online statement.

According to family planning regulations in Jiangsu province, couples who give birth before their marriage is registered face the same fines as married couples who violate the family planning policies — five to eight times the average annual income of the area in which the children were born.

If a couple's annual income is more than double the area's average income, the couple will be subject to additional fines. The amount of any fine depends on the particular county or city that has jurisdiction.

Chen Yuan, a family planning policy lawyer from Pingji Center in Guangzhou, said the couple in this case are unlikely to face a huge fine of 160 million yuan ($26 million), as published in the some media reports.

"If Zhang and Chen's in-come in 2012 exceeded two times the average yearly in-come of local people's, they will pay additional fines, which is one or two times the average yearly income," Chen said.

"Compared to Zhang's in-come, the amount of money is not large," he added.

In 2012, the average yearly income of Wuxi residents living in urban areas was 35,663 yuan.

An authority with Wuxi's commission of population and family planning who spoke on condition of anonymity said that it is difficult to investigate celebrities' in-comes because of the country's faulty taxation system, and Zhang, therefore, may not be fined in accordance with his real income.

"The commission is urging Zhang to declare his real in-come for the years when his three children were born in order to calculate an accurate fine," the source said.

Southern Metropolis Entertainment Weekly reported that Zhang, 62, had at least seven children by several women — an ex-wife, two mistresses and Chen, a former dancer who is 31 years his junior.

In the statement posted on the studio's micro blog, Zhang denied that he had seven children and said that "some people with ulterior motives" followed his children for two years and fabricated rumors that "severely interfere with the daily lives" of his family members.

The incident has caught public attention more than other cases of family planning violations as it exposes the social divide between rich and poor and fuels concerns that the policy has lost its constraining effect on celebrities, experts say.

"Zhang's violation of the family planning policy was initially a personal issue. The reason it has drawn so much attention is that people are concerned that celebrities can override the law and dodge punishment," said Lu Jiehua, a professor of demography at Peking University.

Lu said the incident could also have an adverse effect on compliance, which is high among government employees who fear they could lose their jobs after a violation.

"This incident shows that the policy is not equally effective for celebrities," Lu said. "Nor is it effective for migrant workers, the self-employed or people living in remote areas, to my knowledge."

China's family planning policy has been in place for more than three decades. Most couples have been restricted to only one child since 1980.

But the policy has been loosened over time. A second child was allowed, for example, for some rural families whose first child was a girl, as well as for ethnic groups and for couples who are both only children.

The policy was further relaxed last month, when the Third Plenary Session of the 18th Communist Party of China Central Committee decided that if just one spouse is an only child, the couple may have two children.

Yuan Xin, a professor of population studies at Nankai University in Tianjin, said the fact that Zhang was investigated for the violation shows that there is no privilege for celebrities.

"Anything to do with celebrities is eye-catching. But the fact that Zhang eventually decided to apologize and cooperate with the investigation shows there is no privilege for celebrities, and everybody is equal before the law," he said.

Born in 1951, Zhang is one of China's most renowned filmmakers. His early works, including Red Sorghum and Raise the Red Lantern, won him international acclaim.

He was also the master-mind of the spectacular opening ceremonies of the Beijing Olympics in 2008.

Luo Wangshu contributed to the story.