A 2-month-old boy found dead in West Philadelphia last week starved to death, and police said yesterday that his death is being investigated as a homicide.

The infant, Quasir Alexander, was found at the Traveler's Aid Shelter, on 49th Street near Arch - where he lived with his mother, twin brother and four other siblings - after medics were called early on Dec. 23, police said.

When they arrived at the shelter, which houses recently homeless people and provides food and baby formula to residents, they found little Quasir unresponsive, and he appeared to be undernourished, police said. He was taken to Children's Hospital of Philadelphia and pronounced dead about 6 a.m., police said.

His death was ruled a homicide after the medical examiner determined that he died because of starvation and dehydration, cops said.

The shelter is located in the Kirkbride Center, which rents out space to Traveler's Aid. It takes in recently homeless people who have been referred to them by the Philadelphia Office of Supportive Housing, officials said.

Quasir and his family were receiving help from a provider agency contracted by the Department of Human Services, said a source close to the investigation.

DHS had no open investigation of neglect or abuse for the family, and the caseworkers who worked with them were not DHS staffers, the source said.

However, DHS is now involved in the investigation into the baby's death, said Alicia Taylor, a DHS spokeswoman.

Quasir's siblings are now in foster care, the source said.