Is the statement of a *Dhimmi* accepted regarding the status of a female slave he claims is his daughter or sister?

Primary text

There are two narrations concerning this. The first is that his statement is accepted. Al-Khallal stated this is the more probable opinion because the default is his lack of ownership over her. The second narration states his statement is not accepted without proof because the slave is in his possession, making the situation analogous to his livestock.