
"Of the 56 witnesses listed, many have gone missing, while businessman Prachuab Sangkhao, the key prosecution witness in the case, cannot be located," an EC official said on condition of anonymity.
The official voiced suspicion of foul play to foil the investigation and prevent EC from prosecuting the main coalition party.
The case came to light two years ago when the Department of Special Investigations (DSI) launched a probe over suspicions of the public relations company Messiah being involved in laundering funds donated to the main coalition party by a listed company.
The DSI cited the security and exchange law to look into the matter, before forwarding its report to the EC to widen the investigation. The EC subsequently appointed a committee to question the witnesses again because its mandate differs from that of the DSI.
The deadline for the EC investigation is set for July 21, though it will probably not be met because several witnesses cannot be located.
EC member Sodsri Sattayathum said she was kept informed about the problems and has advised the panel to speak to DSI investigators and confirm the witnesses' statements.
She said despite the snag, she expects the case to proceed, adding that the missing witnesses would not be critical enough for the case to collapse.