Are the fruits produced from seeds purchased with ill-gotten money considered unlawful (haram), and is it forbidden to eat from them?

It is not forbidden to benefit from and eat the fruits that a person has obtained, but he must repent to Allah and return the ill-gotten money to its owner or his heir. If that is not possible, or if the money does not belong to a specific owner, then he must donate it to the poor and needy or spend it on general Muslim welfare.