I don't know who are the 10 most powerful ones. But considering the policy was introduced in 1979. So for any politicians who were married before 1979 and started to have a family then, they may have more than 1.

At the same time. I read frequently from Chinese news that government officials under 60s charged with corruptions. Most of them have several mistresses and had a child with each of them. I don't think that will be counted officially since in China such non martial relationships are not legal.