A total of 139 grave sites and 28 human-trafficking camps have been found in a remote northern Malaysian border region.

A total of 139 grave sites and 28 human-trafficking camps have been found in a remote northern Malaysian border region, the country's top police official told reporters Monday.

National police chief Khalid Abu Bakar revealed the findings at a press conference a day after the government announced the discovery of camps and graves, the first such sites found in Malaysia since a regional human-trafficking crisis erupted earlier this month.

"(Authorities) found 139 suspected graves. They are not sure how many bodies are inside each grave," Khalid said.

He added that the number and size of the 28 camps found suggested that they may have housed a combined hundreds of people.

The largest could hold up to 300 people, another had a capacity of 100, while the rest could hold about 20 each, he said.

The discovery is the latest evidence of the lethal nature of the region's human-trafficking trade.

Malaysian officials had subsequently dismissed the suggestion that similar sites existed on Malaysian soil.

Khalid said the camps and graves were in jungly, mountainous areas that were difficult to reach.

Rights groups have long accused Malaysian authorities of not doing enough to contain human-smuggling.

Thailand launched a crackdown on human-smuggling following the discovery of its mass graves.

The move appears to have caused nervous traffickers to abandon their human cargo at sea, leaving boats filled with hundreds of starving migrants seeking to land in Malaysia, Thailand and Indonesia.