He was minister of forest, horticulture, soil conservation and the department of municipal administration, housing & urban development (2017-2020) in the Biren Singh-led coalition government.
He had been arrested in October 2006 at Indira Gandhi International Airport, Delhi, and was accused of being a member of Kanglei Yawol Kanna Lup and working as a liaison between KYKL and the United National Liberation Front.
[4][5] In January 2017, Khoirom Ranjeet, the leader of the banned Kangleipak Communist Party, Poirei Meiti who was recently arrested for an extortion and kidnapping ring, was revealed to have links to Shayamkumar.
In 2017, he joined Bharatiya Janata Party and was made Minister of forest, horticulture, soil conservation and the department of municipal administration, housing & urban development in the Biren Singh-led coalition government.
A disqualification case against Shyamkumar was registered by the 15 Indian National Congress MLA's which included T. N. Haokip, Md Fazur Rahim and K. Meghachandra.