A forensic report has confirmed that a woman and her three children found dead at their home in Lahore’s Valencia Town died after consuming potassium cyanide, marking a major development in the ongoing investigation into the high-profile case.

According to police sources, the forensic analysis concluded that all four deaths were caused by the highly toxic chemical potassium cyanide.

The investigation is being carried out jointly by Lahore Police and a two-member team from the US Federal Bureau of Investigation (FBI), as the deceased woman, identified as Aleena, her husband Nasir and their three children were all US citizens.

Police have taken three people into custody, including a chemical store owner, another trader and a delivery rider, as part of the investigation.

A female friend of Aleena, who had also been detained for questioning, was later released.

Investigators are also examining Aleena’s mental health history, with investigative sources claiming she had been suffering from mental illness.

According to the investigation, Aleena first contacted a person selling chemicals in Pakistan through social media while she was in the United States and requested that the poison be shipped to her there.

After the request was declined, she allegedly purchased a bottle of potassium cyanide from a shopkeeper in Lahore’s Chungi Amar Sidhu area by transferring Rs138,000 through MoneyGram.

Police said the Chungi Amar Sidhu shopkeeper had obtained the chemical from a trader in Lahore’s Akbari Mandi for around Rs6,000.

After returning to Pakistan, Aleena allegedly had the poison delivered to the house of a friend, from where a rider transported it to her residence a day before the incident.

Investigators also found that she had searched her mobile phone for methods of ending her own life and those of her family.

Based on mobile phone records and other evidence, police detained the delivery rider, the Chungi Amar Sidhu shopkeeper and the Akbari Mandi trader for further questioning.

Officials said all aspects of the case were still being examined.

In a separate development, investigative sources said the polygraph test report of the children’s father, Nasir, had been received and cleared him of involvement in the deaths.

According to the sources, polygraph experts questioned Nasir on eight points relating to the deaths and his wife’s medical condition before concluding that there was no indication he had killed his wife or children.

The case came to light on July 17, 2026, when Aleena, 40, and her three children — 16-year-old Rehan, 11-year-old Arshia and nine-year-old Arsal — were found dead inside their Valencia Town home.

Initial police findings suggested the children had consumed poisoned food before Aleena also ingested the same substance.

Police and forensic teams collected evidence from the scene, while the bodies were shifted to hospital for post-mortem examinations.