The investigation into a Delhi couple’s allegations of an embryo “mix-up” during an IVF procedure remains inconclusive more than two months after DNA samples were collected from the couple and their twin daughters, with investigators saying the probe has stalled because the alleged donors have not yet come forward to provide samples.Photo for representation (AP)Rahul Rathore (41) and his wife Meenu underwent IVF treatment at a fertility hospital in south Delhi’s Greater Kailash. The couple, who already have two daughters, said they opted for IVF to “expand their family”.An investigating officer said police are still awaiting reports from the Forensic Science Laboratory (FSL) in Chanakyapuri and are yet to determine whether the twins are biological siblings, half-siblings or entirely unrelated.“Based on statements of hospital doctors, who have claimed the couple were informed that donor sperm and eggs would be used, and the couple’s allegation that private DNA tests showed the girls are not their biological children, it appears the Rathores are not biologically related to the twins,” the officer said.“The final DNA report is still pending because we also want to establish whether the girls are siblings or half-siblings or completely unrelated,” the officer added.Investigators said they obtained details of potential donors from hospital records and approached two individuals for DNA samples more than a month ago. However, neither has joined the investigation so far. “These donors are legally entitled to anonymity. If they continue to not cooperate, we will place the available DNA findings before the court during the trial proceedings,” the officer said.Two other officers confirmed that police are still trying to establish how many donors, if any, were involved in the IVF procedure.A senior officer said investigators were examining multiple possibilities. “The first possibility is that no donors were used and both girls belong biologically to the couple, although this currently appears less likely. Another possibility is an embryo mix-up in which another couple’s embryo was implanted in the woman,” the officer said.“There is also the possibility that one or both gametes used in the procedure came from donors. In that scenario, the girls may either be half-siblings or unrelated biologically. In such a case, there could have been three or even four donors involved. We have to look at every possibility.”The controversy surfaced in January, days after the twins were born, when the couple allegedly became suspicious because the children had “different facial features”. The family subsequently approached private laboratories for DNA testing and claimed the results showed that neither child shared DNA with either parent.Following a court intervention, an FIR was registered on March 31 under sections related to cheating, criminal breach of trust, criminal conspiracy and criminal intimidation, along with provisions of the Assisted Reproductive Technology (ART) Act. The case is being monitored by senior officers. Three doctors and a hospital official have been named in the FIR.Police had earlier taken the couple and the twins to AIIMS between April 20 and April 22 for independent DNA sample collection.Investigators said the probe has become complicated because of conflicting claims made by the two sides. While the couple allege an embryo mix-up, hospital officials have reportedly produced a consent form and maintained that the couple were informed their own gametes were not reproductively viable and that donor material would be used.Police are now examining records of other couples who underwent IVF treatment at the hospital between May 10 and May 20, 2025, the period during which the Rathores underwent treatment and five embryos were allegedly implanted.The couple, however, deny ever consenting to the use of donor sperm or eggs and have alleged that the consent documents produced by the hospital are forged. “We never agreed or gave consent for donors at any point during the treatment,” Rahul Rathore said, adding that the family was still waiting for the FSL report.Officials at the FSL confirmed on Thursday that the DNA analysis remains pending because of a backlog of cases.