It is the second time this month an immigrant child has died while being detained after crossing the US-Mexico border, reported BBC.

In the previous such incident, seven-year-old Jakelin Caal, also from Guatemala, died after he was taken into custody.

Texan congressman Joaquin Castro said the name of the new boy who died in the US custody as Felipe Alonzo-Gomez.

He also called for a congressional investigation into the death of the minor.

"I’m deeply saddened by the death of 8-year-old Felipe Alonzo-Gomez last night in U.S. Customs and Border Protections (CBP) custody and offer my condolences to his family. While the CBP notified Congress within 24 hours as mandated by law, we must ensure that we treat migrants and asylum-seekers with human dignity and provide the necessary medical care to anyone in the custody of the United States government. Congress should investigate this tragedy upon its return to session," said Castro in a statement.

He said: "The Administration’s policy of turning people away from legal ports of entry, otherwise known as metering, is putting families and children in great danger."

"We learned this first-hand last week during our Congressional oversight trip to Lordsburg Station. Serious concerns were raised about the condition of CBP detention facilities, and the lack of adequate medical supplies, equipment and resources to properly treat migrants and the agents working there," he said.

"Many questions remain unanswered, including how many children have died in CBP custody. With two deaths that we know about just in the last few weeks, Congress will continue to press the Department of Homeland Security until we get answers to all our questions,” Castro said.