YZ (Declaration of Parentage: BATUK: DNA Evidence), Re

In an application for a declaration of parentage, the applicant bears the burden of proving biological parentage on the balance of probabilities. Reliable DNA evidence may establish paternity conclusively where challenges to the chain of custody and identification of samples are speculative and unsupported. The court should distinguish reasonable scrutiny of expert evidence from fanciful allegations that do not undermine its reliability. A declaration should be refused on public-policy grounds only where making it would be manifestly contrary to public policy. The court may consider lies and inconsistencies in accordance with the Lucas direction, assessing why they were made and avoiding the assumption that a lie on one issue proves dishonesty generally.

RS applied under the Family Law Act 1986 for a declaration that UVW was the father of her son, YZ. RS said that she had had a sexual relationship with UVW while he was stationed with the British Army Training Unit in Kenya and that YZ was conceived during that period. UVW denied knowing RS or having sexual intercourse with her.

DNA samples were taken from YZ in Kenya and from UVW at King’s College London. Expert evidence assessed the results as more than one billion times more likely if UVW was YZ’s father than if the father was an unrelated man of East African heritage, corresponding to a probability of paternity exceeding 99.9999999 per cent. UVW challenged the chain of evidence, the labelling of his sample and the reliability of the testing. He also argued that public policy required refusal of the declaration because RS had allegedly misled the court.

The central issues were whether UVW was YZ’s biological father and whether any public-policy exception prevented the declaration.

1. Declaration made. The court found that UVW was YZ’s biological father and made the declaration of parentage. The applicant had established paternity on the balance of probabilities.
2. The expert evidence was reliable. Proper procedures had been used when collecting, sealing, identifying, storing and analysing the samples. The error in the expert’s report as to the date on which UVW provided his sample was a corrected typing error with no evidential consequence.
3. The challenge based on sample mislabelling or substitution had no merit. UVW had attended King’s College London, identified himself, consented to sampling and provided a sample bearing unique identifying information. The hypothesis that his sample had been exchanged with that of another man who shared at least two of his names and was also YZ’s biological father was fanciful and lacked credibility.
4. The court accepted RS’s evidence that she and UVW had had a sexual relationship during the likely period of conception. Her use of UVW’s name on the birth certificate supported her honest belief that he was the father, although it did not itself prove paternity. UVW’s changing account about whether he had met RS was inconsistent with the other evidence. Applying the Lucas direction, the court found that he had knowingly misled the court to conceal the possibility of paternity, while making no finding that RS had misled the court.
5. There was no basis for ordering repeat DNA testing. The DNA evidence put paternity beyond reasonable doubt, and further delay would prejudice the applicant and child.
6. Under section 58(1) of the Family Law Act 1986, the declaration was not manifestly contrary to public policy. The respondent’s public-policy argument therefore failed.

The judgment describes earlier directions and hearings in the same first-instance proceedings:

• High Court (Family Division): On 3 October 2025, Sir Andrew McFarlane P directed DNA testing and made preliminary findings as to jurisdiction.
• High Court (Family Division): On 23 February and 24 March 2026, the matter returned for consideration of the completed DNA testing and the respondent’s position.
• High Court (Family Division): Mr Justice Poole heard the contested application on 5 June 2026 and, on 26 June 2026, made the declaration of parentage.