Father and son die of suspected drug overdose at family birthday party

Joseph and Carlos Andrade told their partners they were going out for a smoke

Police are investigating the deaths (GETTY IMAGES)

A father and son reportedly died of a suspected drugs overdose while celebrating a family birthday party.

Joseph Andrade, 44, and his 22-year-old son, Carlos, excused themselves from the festivities in Brooklyn, New York, by telling their partners they were going out for a smoke.

Carlos' girlfriend, Jasmin Santos, later found him with his face turning purple just inside the building's doorway, the New York Post reports.

Ms Santos, who is mother to Carlos' 11-month-old and 4-year-old sons, "found Carlos dying," a cousin, Sonia Santos, told the paper.

"She screamed and tried to help him. She said he was turning blue."

His father was found unconscious a few feet away.

Investigators suspect they snorted a mix of heroin and fentanyl, police sources told New York Post.

Police arrived and administered Narcan, a drug which can reverse the effects of an opioid overdose.

The father and son were taken to hospital where they were pronounced dead.

Police were later seen investigating a small red plastic bag found on the ground near the two men.

People who knew them said that while the father may have struggled with addiction, the son wasn't known to have a history with drugs.

“The father had a problem,” a neighbour told the paper. “People knew. I was surprised Carlos was involved. He was a good son.”

Their deaths are under investigation and a medical examiner will determine the cause.

Last week, US President Donald Trump declared the opioid addiction crisis a "public health emergency."