It was discovered in July that truckloads of sand had been removed outside a planned resort at Coral Spring beach.
Detectives say people in the tourism sector could be suspects, because a good beach is seen as a valuable asset to hotels on the Caribbean island.
But a lack of arrests made since July have led to criticism of the police.
The beach at Coral Springs, in Jamaica's northern parish of Trelawny, was 400 metres (1,300ft) of white sand. The 0.5-hectare strand was to form part a resort complex costing US$108m, but the theft of its most important feature has led to its developers putting their plans on hold.
Illegal sand mining is a problem in Jamaica; the tradition of people building their own homes here means there is a huge demand for the construction material. However, the large volume and the type of sand taken made suspicion point towards the hotel industry.
The disappearance was deemed so important that the Prime Minister, Bruce Golding, also took an interest in the theft and ordered a report into how 500 truckloads of sand was stolen, transported and presumably sold.
Three months on, and with no arrests or charges in the case, the main opposition People's National Party have suggested that some people now think there has been a cover up.
But the deputy commissioner for crime at the Jamaica Constabulary Force, Mark Shields, insisted this was not an open-and-shut case.
"It's a very complex investigation because it involves so many aspects," he told the BBC.
"You've got the receivers of the stolen sand, or what we believe to be the sand. The trucks themselves, the organisers and, of course, there is some suspicion that some police were in collusion with the movers of the sand."
Police said they were carrying out forensic tests on beaches along the coast to see if any of it matches the stolen sand.