The arrested accused have been identified as Jitendra Yadav, Jitendra Shakya, Pramod Shakya and Punjab Singh, a retired soldier. Cases have been registered against them under the Narcotic Drugs and Psychotropic Substances (NDPS) Act and other relevant sections, and further investigation is underway, police said.

Official sources said the Etah recovery is suspected to be linked to Varanasi-based drug trader, Shubham Jaiswal, who is allegedly associated with an international drug syndicate.

A lookout circular has already been issued against him, while his father was arrested earlier from Kolkata. The main accused remains absconding, officials said.

In a separate development, Mirzapur police arrested two more accused -- Ajit Yadav and Akshat Yadav -- in connection with a case of illegal supply of codeine-based cough syrup registered at Adalhat police station. The arrests were made on Sunday evening following sustained investigation of the suspects, police said.

According to officials, the two accused had allegedly floated firms using forged Aadhaar cards and supplied cough syrup through fake documentation.

During investigation, police found that transactions worth over Rs 1 crore had been routed through bank accounts opened in Varanasi in the name of the fake firms.

Police said Akshat Yadav, proprietor of a firm named A K Distributors, was supplied around 36 litre of New Phensedyl cough syrup (100 ml bottles) from a trader based in Ranchi, Jharkhand.

The firm was found to be non-functional on the ground, and records showed it had been opened only once or twice without carrying out any genuine pharmaceutical business.