The badly decomposed body of a Bronx mother of five was found in a Pennsylvania basement over the weekend — more than a week after her boyfriend was discovered with her car and arrested, a police source told The Post on Monday.

The corpse of 50-year-old Vianela Tavera was found in the home in the Philadelphia neighborhood of Feltonville around 8 p.m. Sunday after homicide detectives investigating tips on Tavera’s disappearance were led to the residence, cops said.

Neighbors also called police to report a foul odor coming from the home, NBC New York reported.

The body was so badly decomposed that authorities could not immediately make a positive identification after the discovery.

Tavera was last seen July 28 leaving her home on Elder Avenue in the Soundview section of the Bronx. She told her family she was going to visit a man she had been dating in Philadelphia, police sources said.

Three days later, cops in Fairfax, Va., arrested her boyfriend, 38-year-old Luis Negron-Martinez of Philadelphia, after he was found with Tavera’s car, sources said.

When the cops there looked in the car, they found a gun and blood in the back seat, according to sources.

Martinez, according to sources, told police he killed someone and went berserk. Authorities took him to a mental hospital.

He eventually was charged with grand larceny and possession of a concealed weapon, sources said.

Tavera had been dating Martinez for about a year, sources said.

Martinez is affiliated with the house where the Bronx mom’s body was found, but it was not immediately clear how.

Neighbors said Monday that Tavera drove a school bus.

“She was a very nice person. Very normal. I thought she left for vacation. She really liked the summer. She liked hot weather,” said Maria Gonzales, 48, who lived downstairs from Tavera.

Another neighbor, Fernando Rodriguez, 83, called Tavera “beautiful.

“She gets along with everyone on the block. I’m so sad about [her death],” Rodriguez said.