A DNA test proved that Jordan Adlard Rogers was a child of Charles Rogers (deceased) and therefore his heir.  

Illegitimate children have the same right to benefit from their parents' estates as children born of the parents' marriage if the parent has not made a will.   

Where the parent has written a  will giving the estate to his or her "children", anyone who can prove they are a child will inherit. 

Where only the legitimate children are named in a will as beneficiaries, an illegitimate child may claim against the estate under the Inheritance (Provision for Family and Dependents) Act 1975.  They may well have to prove their entitlement to apply under the Act by a DNA test.   And the success of the claim will depend on their circumstances, the size of the estate, the financial situation of the beneficiaries and other factors such as whether there was a relationship between the parent and the applicant.