The Punjabi singer died at his residence in suburban Goregaon, Additional Commissioner of Police (north region) Fatehsingh Patil told PTI.
Asked if it was a natural death or suicide, the police official declined to comment.
Janjua, a bhangra and hip-hop singer and songwriter, was best known for his bhangra number "Mundiyaan Toh Bach Ke", which was remixed by Panjabi MC in 1998 and re-released in 2002.
He had also sung some popular Bollywood songs "Dance Pe Chance" from "Rab Ne Banaa Di Jodi", "Soni De Nakhre" from "Partner" and "Dil Kare Chu Che" from recently released film "Singh Is Bliing".
More From This Section
Salim Merchant tweeted, "Heard about the sudden demise of singer Labh Janjua. What a fab artist... Prayers and condolences to the family #LabhJanjuaRIP"
"Shocked to hear about Labh Janjwa's untimely demise... Life is so uncertain...," Shaan posted.
Singer-actor Ayushmann Khurrana said his voice will be missed.
"RIP Labh Janjua. Your voice will always remain immortal. It carried the soul of Punjab."
"Punjabi singer -#LabhJanjua no more! Really shocking news! Life can be so unpredictable," Harshdeep Kaur posted on Twitter.