An 8-year-old boy from Guatemala has died in US Government custody early on Christmas Day, according to US immigration authorities, marking the second death of an immigrant child in detention this month.

Key points: The boy showed "signs of potential illness" on Monday and received treatment

The boy showed "signs of potential illness" on Monday and received treatment Guatemalan consul in Phoenix confirmed the boys name was Felipe Gomez Alonzo

Guatemalan consul in Phoenix confirmed the boys name was Felipe Gomez Alonzo His death is the second this month, after 7-year-old girl Jakelin Caal

US Customs and Border Protection (CBP) said in a news release that the boy died shortly after midnight on Tuesday (local time).

The boy showed "signs of potential illness" on Monday and was taken with his father to a hospital in Alamogordo, New Mexico, the agency said.

There, he was diagnosed with a cold and a fever, was given prescriptions for amoxicillin and Ibuprofen and released that afternoon.

The boy was returned to the hospital in the evening with nausea and vomiting and died there just hours later, CBP said.

The agency said the cause of the boy's death has not been determined and that it has notified the Department of Homeland Security's inspector general and the Guatemalan government.

CBP promised "an independent and thorough review of the circumstances".

The border agency said it would be conducting new medical checks on every child in its custody in response to the death, saying in a statement that it would focus those checks on children under the age of 10.

It has not yet said when the father and son entered the United States or how long they were detained, saying only in its statement that the boy had been "previously apprehended."

But according to Guatemala's foreign ministry, the father and son entered the US at El Paso, Texas, on December 18, then were taken to the Border Patrol's Alamogordo station on Sunday.

Oscar Padilla, the Guatemalan consul in Phoenix, confirmed that the boy's name was Felipe Gomez Alonzo.

The consul says he interviewed the father, 47-year-old Agustin Gomez, by telephone.

Guatemalan girl's body returned home

A 7-year-old Guatemalan girl died earlier this month after being apprehended by border agents.

The body of the girl, Jakelin Caal, was returned to her family's remote village on Monday for a memorial service.

News of the death came a day after the family of Jakelin Caal Maquin held a memorial for the 7-year-old girl. ( AP: Oliver de Ros )

Villagers wept and watched curiously as the body, carried in a white coffin, arrived at the home of Jakelin Caal's grandparents in San Antonio Secortez.

Relatives had set up a modest wooden altar flanked by vases and overflowing with flowers, photographs of the child and the hand-lettered message, "We miss you".

The girl and her father, Nery Gilberto Caal Cuz, had been traveling with a group of 163 migrants who were arrested on December 6 near a border crossing in New Mexico.

The father signed an English-language form stating Jakelin was in good health, but it remains unclear whether he understood what the form said.

Hours later her temperature skyrocketed to 40.9 degrees Celsius and emergency medical teams had to revive her.

She was flown to hospital in El Paso, Texas where she died the next day.

Claudia Maquin says "extreme poverty" made her husband and daughter Jakelin leave for the US. ( AP: Oliver de Ros )

Democratic members of Congress and immigration advocates sharply criticized CBP's handling of the death and questioned whether border agents could have prevented it by spotting symptoms of distress or calling for an evacuation by air ambulance sooner.

CBP has said that it took several hours to transport Jakelin and her father from a remote Border Patrol facility to a larger station and then a hospital in El Paso.

The death also came during an ongoing dispute over border security and with a partial government shutdown underway over US President Donald Trump's request for border wall funding.

The White House did not immediately comment on the boy's death Tuesday. CBP officers and the Border Patrol remain on the job despite the shutdown.

AP