A 2009 IAS batch officer of the Karnataka cadre, 41-year-old Senthil said he owed an apology to the people and public representatives of the west coast district in the state for discontinuing from the job midway.
Mangaluru is about 360 km away from Bengaluru.
"I have taken this decision as I feel it is unethical to continue as a civil servant when the fundamental building blocks of our diverse democracy are being compromised in an unprecedented manner.
"I also feel the coming days will present challenges to the basic fabric of our nation and I would be better off outside the IAS to continue with my work at making life better for all," Senthil said in the letter.
Noting that it simply can't be business as usual, the young officer expressed gratitude to all who worked with him in all capacities and in the process a friendship with him.
Senthil had been transferred to head the coastal district on October 19, 2017 from Bengaluru where he was the director of the Mines and Geology department.
District's Zilla Parishad Chief Executive Officer R. Selvamani will officiate as the deputy commissioner, if the state government accepts Senthil's resignation and relieves him from service.
In a related development in Bengaluru, Chief Minister B.S. Yediyurappa asked Chief Secretary T.M. Vijaya Bhaskar to ascertain the reasons for Senthil's resignation and if he could be persuaded to continue in the service.
"When Yediyurappa learnt about Senthil putting in his papers, he asked Bhaskar to discuss the issue with the IAS officer and find out if any pressure was on him for continuing in the service," an official in the chief minister's office told IANS on phone.