A team of independent investigators is alleging that St. Lucia's police force maintained "death lists" of people deemed to be criminals and planted guns at the scenes of police shootings to legitimize their unlawful actions, the Caribbean country's leader announced Sunday.

In a national address late Sunday, Prime Minister Kenny Anthony said a team of Jamaican investigators have delivered an "extremely damning" report looking at the deaths of 12 people fatally shot by police in 2010 and 2011, while another administration was in power. The investigators from the Jamaica Constabulary Force were invited by St. Lucia's government a year after the U.S. withdrew all assistance to island police citing concerns about allegations of unlawful killings.

Quoting from the report, which was not made public, Anthony said investigators found that all the shootings reviewed were "staged by the police" but reported publicly as homicides by unknown assailants. Guns were allegedly planted by officers and members of the police high command may have been involved in covering up the truth about the long-rumored extrajudicial shootings.

"The report confirms that `the blacklist or death lists' referenced by the media, human rights organizations, victims' families and citizens alike did exist,"  Anthony said.

Cameron Laure, president of the Police Welfare Association in St. Lucia, said he was receiving phone calls from "many police officers" about the details disclosed by the prime minister.

"I don't even know how to react at this point. I will have to meet with the commissioner of police as well as the other members first before making a full statement," he said.

Alleged tampering with evidence didn't just happen at scenes of police-related fatalities, Anthony disclosed. During their probe, the investigators disclosed that the server used by some police commanders was "deliberately tampered with," he said.

The dozen killings occurred during a security initiative called "Operation Restore Confidence" as the tourism-dependent island grappled with a worrying rise in violent crime. At the time, former Prime Minister Stephenson King publicly warned criminals that "no stone will be left unturned and there will be no hiding place for anyone."

During the period under review, five of the dozen men fatally shot by police were killed in a single operation in the southern town of Vieux Fort.

In its most recent annual report on the island, the U.S. State Department complained of the "limited progress" of probes into the deadly police shootings. In 2012, local inquests concluded that six of the 12 shootings were justified. But the U.S. imposed its sanctions the following year, indicating they did not have confidence in the outcomes of the inquests.

Anthony said the investigators made 31 recommendations in their report, the main one being prosecutions for "all police officers involved in the unlawful killings of citizens" that they reviewed.

The prime minister said the public prosecutor must now determine whether to pursue cases against the officers.

Anthony said he will not order that suspected police officers behind the alleged unlawful killings "be charged or dismissed or offered packages to retire." But he said the government will now ensure that police recruits receive training in human rights and special prosecutors will be appointed to assist with any future prosecutions of officers, among other changes.

Police Commissioner Vernon Francois, who could not be reached Sunday night, will also continue on leave.