BANGKOK, Thailand (CNN) -- Thai police say two Americans stole adult and infant body parts from a Bangkok hospital and tried to ship them to Las Vegas.
The two men, identified as Ryan Edward McPherson and Daniel Jamon Tanner, told police they wanted to surprise their friends back home, Royal Thai Police Deputy Commissioner Gen. Ruangsak Jritake said.
It was not immediately clear whether McPherson or Tanner had attorneys.
A delivery company intervened in the shipment. On Saturday, a DHL office in Thailand's Pathum Thani province called police after workers there were scanning shipments and discovered the body parts inside three packages.
The packages contained five acrylic plastic boxes, Jritake said.
One box contained an infant's head; another contained a baby's left foot, which was sliced into three pieces, the police official said. The other acrylic boxes contained an adult heart and adult skin.
"We have talked with an American who was trying to send the parcels to the USA, but we could not press any charges on him and we are not quite sure which laws we can apply to him." Bang Pongpang police chief Col. Adisorn Semsawat said over the weekend.
At the time, police said the American told them he found the infant body parts at a night flea market and that he had paid about $100 for them -- though he could not remember where the market was located.
But on Monday, authorities revealed more details on the case.
All the body parts were stolen from Siriraj Hospital, the largest hospital in Thailand, Jritake said. Police said closed-circuit video from the hospital showed two men identified as McPherson and Tanner.
Royal Thai Police are seeking an arrest warrant for the two men and plan to charge them with theft from a government hospital.
But the two men have already left Thailand for Cambodia. If an arrest warrant is approved, Thai officials may have to seek the two men's extradition.
Thai police say they've been in touch with the U.S. Embassy.
The U.S. embassies in Bangkok and in Phnom Penh, Cambodia, did not immediately respond to CNN's requests for comment.
Not the first time
The bizarre discovery is not the first time infant remains have been found in Thailand. In 2010, more than 2,000 illegally aborted fetuses were recovered at a Buddhist temple in Bangkok.
Infant body parts can be bought on the Thai black market. Some Thais practice black magic and believe that supernatural power comes from infant body parts, if the rites are performed by monks or sorcerers. They believe that having the items provides protection and business success and can ward off bad luck.
Police say in 2010, the smell of decay led investigators to the Phai-nguern Chotinaram temple in central Bangkok, where they discovered more than 2,000 illegally aborted fetuses. Three people were arrested, including two morticians who were charged with hiding bodies.
CNN's Andreas Preuss contributed to this report.