Toxicology findings cited in federal court documents show that University of Mississippi students Aidan Hamilton, 18, and Robert Strang, 20, had the same three substances in their blood, according to reporting by Fox News. The students died in Oxford on Sept. 21.

The filing identifies mitragynine, MGM-15 and MGPI. It says the substances were present in Smax Mango Breeze pills that investigators reported finding in the students’ possession. The full toxicology report had not yet been publicly released, according to the source report.

Federal investigators allege that Yahya Mohamed Mosleh and his son, Islam Mohamed Mosleh, were involved in selling products containing controlled substances through Puffs Vape, Tobacco and Beer Store in Oxford. The two men face federal drug charges. Court documents say the students’ bank records showed purchases at the store on the same date, and investigators linked products seized there to the type tested in the overdose investigation.

According to the filing, agents later made a controlled purchase from Yahya Mosleh, and testing found MGM-15 and MGPI in the product. The documents also say he warned the confidential informant that people had died after using similar products. Prosecutors argued there was probable cause to believe the drugs caused the two deaths; that is an allegation, not a final finding of responsibility.

A federal judge ordered Yahya Mosleh held pending trial, citing flight risk and ties to another country, the documents say. Islam Mosleh was granted release on an unsecured $20,000 bond with conditions including a curfew and location monitoring. The cases remain unresolved.