Assistant director in the department, Pradip Kumar Choudhary, had allegedly demanded Rs 1.5 lakh from a supplier for clearing a bill of Rs 12 lakh, inspector Swapnil Das said.
Choudhary agreed on Rs 1 lakh after negotiations with the supplier Nishant Bhardwaj, who had supplied dip irrigation systems for farmers, he said.
Following this, Nishant approached the Lokayukta police, he said.
"We laid a trap and sent the supplier to Choudhary's place this afternoon. The assistant director accepted the bribe and kept it in the refrigerator," said the inspector.
Choudhary has been booked under the Prevention of Corruption Act and further investigation is on, he said.