The owner of a cold storage facility in Prayagraj that collapsed, claiming the lives of four workers and injuring 14 others, was detained on Tuesday, police said.

Ansar Ahmad, the owner of the cold storage facility in Phaphamau area where the incident happened on Monday afternoon, has been taken into custody for questioning, they said.

Deputy Commissioner of Police (Ganga Nagar) Kuldeep Gunawat said an FIR was registered late Monday night against seven named persons and four to five unidentified individuals in connection with the incident.

"Ansar Ahmad has been taken into custody and is being questioned," he said.

The district administration has ordered a probe into the incident. District Magistrate Manish Kumar Verma has assigned the inquiry to Additional District Magistrate (Finance and Revenue) Vinita Singh.

Singh said a preliminary report would be submitted within two days, while a detailed report would be filed within seven days.

According to officials, four workers died and 14 others were injured when a portion of the cold storage collapsed in Chandapur village under Phaphamau police station limits on Monday afternoon. The injured are undergoing treatment at SRN Hospital.

Police Commissioner Jogendra Kumar had said the incident would be thoroughly investigated, including the status of the facility's licence and its renewal.

"We will examine how a structure in such a dilapidated condition was granted a licence. Strict action will be taken against those found responsible," he said.

The collapse also led to leakage of ammonia gas from a storage tank, triggering panic in the surrounding area, officials added.