The body of a 21-year-old MS-13 gang member was found buried in a shallow grave in Long Island this week and cops say he was slaughtered for being an informant.

Carlos Rivas-Majano, 21, of Uniondale, went missing last August but his body was found on Wednesday in a foot-and-a-half deep grave in East Meadow behind Kellenberg Memorial High School.

He was stabbed, slashed, and hacked to death with a machete on August 13, 2017 for being an informant and cooperating with authorities, police say.

His body went unnoticed for a year until Nassau officers acted on tips that led to the grisly discovery, according to News12.

The body of MS-13 gang member Carlos Rivas-Majano, 21, (left) was found in a shallow grave in East Meadow, Long Island on Wednesday. On Thursday fellow gang member Carlos Benitez-Hernandez (right) was charged with his murder

While the motive behind the killing is under investigation, cops speculate he was murdered due to 'the gang's displeasure with his actions within the group or something that they felt was disrespectful to them or a threat to them,' homicide squad commander De. Lt. Stephen Fitzpatrick said to Newsday.

'This is still an active investigation. We are not going to give any additional details at this time,' Det. Vincent Garcia, a Nassau police spokesman, said Friday.

Three law enforcement sources confirmed that Rivas-Majano was an informant to Newsday.

Court records show that Rivas-Majano was arrested when he was 19 in May 2015 on multiple weapon charges after he was allegedly found with a loaded semiautomatic gun in his waistband. On his arrest paperwork it said he was 'not a legal citizen of the United States'.

However in March 2016 he got a deal where he pleaded guilty to a misdemeanor charge and was sentenced to jail time, but the court proceedings and transcript were sealed.

Cops say Rivas-Majano was lured to the grave site last August and was 'viciously and barbarically' attacked by at least five MS-13 gang members.

Cops found his body on Wednesday after following tips and discovered his remains nearly one year after Rivas-Majano was hacked to death, pictured above at the site of the shallow grave

On Thursday cops charged Benitez-Hernandez with second degree murder and they have four other alleged suspects in custody as well, though they are yet to be identified

On Thursday admitted MS-13 gang member and undocumented immigrant Carlos Benitez-Hernandez was charged with second degree murder in Rivas-Majano's death.

Police say they have four other suspects in federal or county custody, but they have not identified them.

Benitez-Hernandez, also of Uniondale, pleaded not guilty in a Hempstead district court arraignment to Rivas-Majaon's murder. He was ordered to be held without bail.

Cops say he 'is a self-admitted MS-13 member' from El Salvador. When he was arrested he was already in federal custody on an immigrant detainer.

He also has 'a violent criminal history, with weapons, gang assault and intimidating a victim' in his background, according to homicide squad commander Fitzpatrick. He had just been paroled before the murder last year.

Rivas-Majano's body was discovered as a joint probe by Nassau authorities, the federal Department of Homeland Security and the US Drug Enforcement Administration.

Ten homicides in Nassau County have been attributed to MS-13 since 2016, including six cases where victims were buried, cops say.

Police say these killings often unfold in the same disturbing fashion where victims are lured to a wooded area.

'That person has been almost lowered into false sense of security, going in to smoke marijuana, hang out, have a little meeting. They just don't know that in that particular case they're marked for death,' Fitzpatrick said to ABC.