The patient was scheduled to be discharged on Tuesday as he had tested negative twice.
The hospital, in a release, said they informed the health department that the man was about to be discharged as he had tested negative twice.
Health minister K K Shailaja has ordered a probe into the matter, a health department release said.
Thiruvananthapuram District CollectorNavjot Khosa on Tuesday sought a report from the Medical college hospital officials.
"Preliminary investigation by the medical college officials shows that the patient was a drunkard and escaped quarantine due to non-availability of liquor.
The surveillance team has started the process of tracing his contacts," a release from the Collector's office said.
The patient is suspected to have travelled in a state-run bus to his native place in Thiruvananthapuram district itself.
Officials said the district administration was trying to gather details of those who travelled in the bus.
Kerala Tuesday reported 91 fresh cases, which include one health worker in the state capital, taking the total persons under treatment to 1,231. RRT APR RAVINDRANATH APR RAVINDRANATH