A US teenager who recently gave birth in prison and her boyfriend have been spared the death penalty for killing the woman’s mother and hiding her body in a suitcase in Bali.

Heather Mack, 19, was sentenced to 10 years in prison for assisting in the killing of her mother Sheila von Wiese-Mack during a holiday on the Indonesian resort island in August.

Her body was discovered in a bloodied suitcase and the court ruled that her boyfriend Tommy Schaefer, 21, battered her to death in a hotel room while Mack helped him stuff the body into the case by sitting on it.

Heather Mack, 19, of the United States holds her baby daughter in a cell (Getty Images)

Schaefer, who was tried by the same judging panel but in a separate case to Mack, was sentenced to 18 years in prison. The charge of premeditated murder carried a maximum penalty of death by firing squad but the Indonesian Criminal Court chose to be lenient towards Mack because she had given birth, according to the Associated Press.

During his trial, Schaefer claimed Mack’s mother became enraged by news of her daughter’s pregnancy and tried to strangle him. He claimed he responded in self-defence by hitting her with a metal fruit bowl, killing her.

"She squeezed my neck for about 20 to 30 seconds. I couldn't breathe. I had blood going to my head and my eyes were so watery," Schaefer was quoted as telling the court by CNN.

"I couldn't see for a moment because my eyes were so watery and I was distraught, I was in a state of mind, I had no idea what was happening. I was almost about to black out. And I grabbed it and I started swinging.”

In pictures: American woman's body found stuffed in suitcase on island of Bali Show all 6 1 /6 In pictures: American woman's body found stuffed in suitcase on island of Bali In pictures: American woman's body found stuffed in suitcase on island of Bali Indonesia A policeman (R) looking at a suitcase where the body of a woman was found inside, displayed at a police station in Nusa Dua on the Indonesian resort island of Bali In pictures: American woman's body found stuffed in suitcase on island of Bali Indonesia The suitcase in Bali where the body of a woman was found inside AFP In pictures: American woman's body found stuffed in suitcase on island of Bali Indonesia A police officer escorts suspect Tommy Schaffer (21) during an investigation at a police office in Nusa Dua on Indonesian resort island of Bali In pictures: American woman's body found stuffed in suitcase on island of Bali Indonesia A police officer escorts suspect Lois Heather (19) during an investigation at a police office in Nusa Dua on Indonesian resort island of Bali In pictures: American woman's body found stuffed in suitcase on island of Bali Indonesia Foreign tourists walking past the St. Regis hotel in Nusa Dua on the Indonesian resort island of Bali. A US tourist's battered body has been found in a suitcase at the exclusive hotel on Indonesia's resort island of Bali and her daughter and daughter's boyfriend have been arrested over the killing, police said. The body of Sheila von Wiese Mack was found into a suitcase in the boot of a taxi in front of the five-star St. Regis hotel In pictures: American woman's body found stuffed in suitcase on island of Bali Indonesia A view of the St. Regis hotel in Nusa Dua on the Indonesian resort island of Bali

Wiese-Mack’s battered body was discovered in the boot of a taxi outside of the St. Regis Bali Resort. Prosecutors said the couple placed the body in the trunk of the taxi and said they were going inside the hotel to check-out and would return, but never did.

During the trial, local media quoted Mack as claiming her mother had threatened to kill their unborn child.