It's simple, let Qi Qin's daughter Qi Xiangsi go plead with Emperor Yongning to open the coffin and perform an autopsy on her father.
Previously, Qi Xiao went to study arts, now in the Imperial City, Qi Qin's only bloodline left is Qi Xiangsi. Over the years, Qi Xiangsi has lived quite well under the protection of the Crown Prince and Princess Anle, as well as Qi Qin's old comrades; no one dares to bully her.
As for spending money, Qi Qin, being the National Guardian General, accumulated a lot of wealth during his lifetime.
After his death, due to his extraordinary merits during his life, and because his two children were still too young, his salary never stopped; it was inherited and collected by his legitimate son Qi Xiao.
It would stop only when Qi Xiao officially worked for the government and had his own salary or other sources of income and explicitly stated he did not need the court's salary.
Otherwise, Qi Xiao could continue to receive the court's salary until death.
