Medan, N Sumatra, Aug. 26 -- North Sumatra police are investigating a drug network that allegedly used a tow truck to conceal the transport of 15 kilograms of methamphetamine, seeking to identify those behind the operation.

North Sumatra Police Narcotics Director Senior Commissioner Andy Arisandi said in Medan on Wednesday that investigators were expanding the case to identify the network's alleged mastermind.

"We are still developing the case because the suspects have repeatedly used this method," Andy said.

Investigators are also tracing the network's controllers to dismantle the drug supply chain, which allegedly uses tow trucks as a cover, Andy said.

Police are monitoring the tow truck, which was traveling from Aceh to Jakarta, he...