A 40-year-old Mexican immigrant died in Customs and Border Protection (CBP) custody Monday, the fourth time a person has died after being apprehended by the agency in recent months.

The CBP says that the man, who has not been identified, died at the Las Palmas Medical Center after being arrested for illegal re-entry on Sunday.

The agency says the man was diagnosed with flu-like symptoms, liver failure and renal failure.

{mosads}“Our thoughts and prayers go out to the family and his loved ones,” CBP Assistant Commissioner for Public Affairs Andrew Meehan said in a statement. “CBP remains committed to ensuring the safe, humane and dignified treatment of those within the care of our custody. Consistent with CBP policy, CBP’s Office of Professional Responsibility has initiated a review.

“The Department of Homeland Security Office of the Inspector General and the Government of Mexico has been notified. At this time, CBP is not releasing the identity of the individual. CBP will release more details as available and appropriate, and will ensure an independent and thorough review of the circumstances.”

This death follows the deaths of three other immigrants while in CBP custody in recent months.

In February, a 45-year-old man died after being diagnosed with cirrhosis of the liver and congestive heart failure.

In December, two children, 7-year-old Jakelin Caal Maquin and 8-year-old Felipe Alonzo Gomez, died in custody, prompting a review of CBP policy.

Jakelin began having seizures roughly eight hours after being taken into custody with her father.

Felipe died after he was transferred to a hospital for exhibiting flu-like symptoms.