An Indian-origin man was among three surveyors who were jailed for four to eight months on Thursday by a Singapore court for accepting bribes to cover up the unauthorised transfer of marine gas to vessels that were supplied to oil giant Shell.Anand Omprekas, 39, along with Malay origin Noruliman Bakti, 40 and Muhammad Khairul Asri Mohamad Hanafiah, 38, pleaded guilty to corruption, having each received between USD 6,000 and USD 25,000 in bribes.