Haridwar, Sept. 21 -- The brother of Surendra Koli on Sunday submitted a complaint at the Saptarishi police outpost in Haridwar on Sunday, seeking a high-level probe into his brother's death, alleging that it occurred in suspicious circumstances.

Surendra Koli, who spent nearly two decades behind bars before being acquitted of all 13 cases related to Nithari killings last year, was found dead at his tea stall in Haridwar on Friday. While it is suspected that he died by suicide, police said the investigation is at an initial stage and the exact cause of death would be established after the post-mortem report.

Chandan Koli told police that the circumstances surrounding the death raised doubts about the possibility of suicide.

"On Saturda...