A probe into the incident has been ordered by the Superintendent of Police, and four personnel posted at the post were placed under suspension.
Kanta (32) and Rukkan Singh (38) were picked up last evening from Morta village.
Kanta had eloped with Singh on May 6 from Jahangirabad area of Bulandshahr and both were staying in a rented room here under Muradnagar Police Station area, he said.
When Kanta's husband, Ravi, came to know about their whereabouts, he lodged a complain at Vardhamanpuram police station following which they were brought to the police post.
Soon after they were brought into the post they consumed Sulphas tablets and fainted, said SP.
They were rushed to a hospital in a critical condition where they died.
Constables Iqbal Haider Zaidi, Lokesh Kumar and Sureshchandra Panwar and station in-charge Vinod Kumar Upadhyaya were suspended with immediate effect, the city SP said.
