Thai Prime Minister Thaksin Shinawatra has denied accusations that his government is operating a shoot-to-kill policy against anyone operating in the drugs trade.
The crackdown is popular inside Thailand
An anti-drugs campaign in Thailand has claimed up to 600 lives in two weeks, and has sparked growing international concern.
But Mr Thaksin said on Friday that "everything had been done according to the law".
The prime minister's comments followed the publication of a news release by human rights group Amnesty International, which alleged the Thai Government was encouraging extra-judicial killings in its eagerness to crack down on drug trafficking.
Mr Thaksin dismissed the accusation. "In fact, we do follow the law," he told reporters.
He argued that police have acted in self-defence.
"There is nowhere on earth that police ask suspects who are about to fire a gunshot to go to court first," the prime minister added.
The police themselves have admitted to killing only 15 of the victims. They said that other deaths were the result of inter-gang warfare.
The way that many victims have been shot and the fact that no investigations of their deaths have taken place has led some Thais to suspect there is an official shoot-to-kill policy in place.
"The effect of the government's campaign against drugs
trafficking has been a de facto shoot-to-kill policy of anyone
believed to be involved in the drugs trade," Amnesty alleged in a statement late on Thursday.
Amnesty said this shoot-to-kill policy had been supported "at the highest level".
Donna Guest, researcher into Thailand and Burma at Amnesty International, admitted that the group had not done its own investigations, but said reports coming from within Thailand were damning.
"Evidence is very suggestive of at least some extra-judicial killing," she told BBC News Online, noting the Thai police's past record for such abuses and the severe pressure on security officials to stem the drugs trade or lose their jobs.
Ms Guest said that Thailand's Forensic Science Institute had reported that the authorities were obstructing the work of pathologists, and that bullets had been removed from corpses.
The Thai leader promised that police would investigate.
"When we clean up a house, dust billows. Don't panic," Mr Thaksin told reporters.
But Amnesty was less phlegmatic.
"It is a sad fact that after 10 years of significant improvement in Thailand's human rights record, the government has now taken a
big step backwards," the group said.
Amnesty urged Bangkok to initiate an independent inquiry into the killings.