Dozens of live monkeys were found stuffed inside bags after a failed wildlife trafficking operation in Thailand.

The primates - some juveniles - were discovered after locals heard them crying in an abandoned house in Saraburi province on February 17.

Each monkey had been secured in zip-tied net bags so they could not escape before being crowded inside crates where ten of them reportedly have died from starvation or suffocation.

Officials said there were four boxes each containing six to eight monkeys - 29 in total and one that had died - with each of them appearing tired and dehydrated. A further 10 dead baby monkeys were discovered outside the building.

The animals were sent to the Central Wildlife Rescue Center for observation while local police searched for the smugglers in an ongoing investigation. They face up to five years in prison.

Police Captain Navarot Kraiyachaem said: 'We believe that the smugglers were preparing to take the monkeys to their destination but postponed due to a checkpoint.

'They may have hidden the monkeys here because it's an area away from houses so motorists rarely pass by here.'

Resident Pirom Pranavy, 42, said she and her sister were passing by the abandoned structure when they heard the monkeys so they pulled over and saw a dead baby monkey lying in the front yard.

She said: 'We thought there were only one or two more inside but when we entered there were lots of them. Some have already escaped into the trees so we called the police.'

Animal Rehabilitation and Reservation department director Suttipong Kaemtubtim said the monkeys were a type of macaque which was a protected species.

He said: 'These monkeys are protected species. Our team gathered the monkeys back to our facility before they were sent to a rehabilitation centre in Nakhon Nayok province.'

Investigation on the incident is ongoing but smugglers could face up to five-year jail time and 500,000 baht fine once caught.