One person was arrested and five others, including a pregnant woman, were booked in connection with a sex determination test at Samana town in the district on Friday.
The arrested accused was identified as Anoop Singh, who works as laboratory technician at a private hospital in Kurukshetra.
Three of those booked were identified as Lakshami, a pregnant woman, her husband Ashwani Kumar, residents of Ambala, Major Singh, a resident of Ghagga in Patiala, while the remaining two were yet to be identified.
Ambala deputy civil surgeon Dr BB Lala, the complainant in the case, said they were keeping a track of the activities of Anoop Singh, who was involved in similar cases earlier also.
After getting a tip-off that Anoop was still conducting sex tests, Dr Lala used a nurse, who was pregnant, as a ploy to approach the accused for conducting test. When the nurse contacted the accused, he demanded `25,000 for the test.
Dr Lala said when the deal got matured, Anoop directed the nurse to reach Ambala on February 10. He said he, accompanied by a team of doctors, followed the nurse. The accused couple, Lakshami and Ashwani, joined them near Shambu at Patiala.
Anoop later took the nurse, Lakshami and Ashwani to Samana where the nurse and Ashwani handed over the money to him.
In the meantime, Dr Lala said, they informed the local administration, including Patiala deputy commissioner, about the proposed illegal tests.
He added that later a man came on a bike and drove away both the pregnant ladies.
Anoop, who conducted the test at Dharma nursing home in Samana, was later arrested while the other accused managed to flee, Patran station house officer (SHO) Dharamdev Singh said.
He added the police recovered rs 18,000 from the possession of the accused that was given by the accused Lakshami and the nurse used as a ploy.
The SHO said the police registered a case under sections 3-A, 4(4), 5(2), 6(B), 23(3) of rule 4(2) of Pre-Conception and Pre-Natal Diagnostic Techniques (PCPNDT) Act, 1994.
He said during the investigation, Anoop told the police that they had placed a portable ultrasound machine that was immediately removed after conducting the tests.
The SHO said the police were making efforts to trace the other accused, who were still absconding.
Dr Lala said during the preliminary investigation it had come to the fore that accused Lakshami and her husband Ashwani had three daughters.