A team of scientists visited Andhra's Eluru where many people fell sick with mystery illness.
A nine-member team from National Institute of Nutrition (NIN), Hyderabad visited the town.
The scientists collected samples of water, food along with blood and urine samples of patients.
Earlier, Andhra Pradesh CM Jagan Mohan Reddy had visited Eluru govt hospital.
CM Reddy had met patients who were afflicted by the unknown disease.
More than 300 people were affected with the mystery disease in Eluru.
A team of AIIMS doctors had also collected samples of patients for further tests.
Around 200 patients were discharged from the hospital after treatment.
The outbreak started in the One-Town area of Eluru and claimed one life on December 6.
So far, authorities have not been able to identify the origin of the disease.
The mysterious disease saw people falling unconscious after fits and nausea.
