There are several Sikh political prisoners who were involved in a civil rights movement in Punjab and subsequently charged under Terrorist and Disruptive Activities (Prevention) Act which has been criticised by various human rights group as its provisions contained human rights abuses.
Some of the Sikh Prisoners include: Devinder Pal Singh Bhullar Jagtar Singh Hawara Lal Singh Paramjit Singh Bheora Lakhwinder Singh Gurmeet SIngh Waryam Singh Shamsher Singh Subeg Singh Gurdeep Singh Khera Gurmeet Singh Foji Daya SIngh Lahoria
In order to seek their release there have been several protests globally including a hunger strike by Surat Singh Khalsa.
References
Sikh political prisoners Wikipedia(Text) CC BY-SA