Utah Code § 81-5-508: Genetic testing when specimens not available.

(1) Subject to Subsection (2), if a genetic-testing specimen is not available from a man who may be the father of a child, for good cause and under extraordinary circumstances the tribunal considers to be just, the tribunal may order the following individuals to submit specimens for genetic testing:

(a) the parents of the man;

(b) brothers and sisters of the man;

(c) other children of the man and their mothers; and

(d) other relatives of the man necessary to complete genetic testing.

(2) Issuance of an order under this section requires a finding that a need for genetic testing outweighs the legitimate interests of the individual sought to be tested.