A daughter of Sharmila Nebhrajani, who joined the Charity Commission's board in July, has attended a private nursery, according to a commission spokeswoman.
"She plans to send that child to a state establishment," said the spokeswoman. "If the child stays on in the independent sector, then Nebhrajani will have to absent herself as well."
The news follows last month's announcement that Dame Suzi Leather, chief executive of the regulator, would not take part in decisions on the charitable status of private education institutions because of a conflict of interest - her daughter attends a private school (Third Sector, 22 August).
There might be further conflicts to consider now it has emerged that six of the commission's nine board members, including Leather, were privately educated. A commission spokeswoman told Third Sector that Nebhrajani, John Williams, Simon Wethered, Theo Sowa and Andrew Purkis all went to independent schools.
One legal expert, who has asked to remain anonymous, said this raised a potential conflict of loyalties. "If people who have previously been to private schools still have connections with them, are their judgements independent?" the expert asked.
"It is not only about whether they are independent, but also whether they are seen to be so. If any of the six have maintained old-boy connections, such as subscribing to newsletters, being trustees or helping with careers events, it should be acknowledged. It is a potential conflict of loyalty."
The commission's guidance for charity trustees warns that individuals should guard against situations in which their loyalty to charities "conflicts with their loyalty to the bodies that appointed them, to other charities of which they are trustees or to members of their families".
Separately, Jonathan Shephard, general secretary of the Independent Schools Council, has described Leather's decision to absent herself from the public benefit discussions as "odd".
"As regulator, to excuse yourself from a decision involving a huge part of the charitable estate seems excessively cautious," Shephard said. "If you are a member of a faith group, do you have a conflict of interest talking about religious charities? What will happen when it goes to court? Most judges will have been educated in either the state or independent sectors."
Shephard said he would be writing to the commission to complain about Leather's comments in an interview in The Times that some schools would not comply with new regulations and that the public benefit issue would inevitably reach the Charity Tribunal. "She has no basis for saying that," he said.