A pregnant Briton sentenced to life imprisonment in Laos for trafficking heroin has arrived back in Britain to serve out her jail term.

Samantha Orobator was sentenced in June after pleading guilty to drug trafficking. She became pregnant in prison.

Orobator, 20, was met by a prison van Friday as she got off the flight from Laos at London's Heathrow Airport.

"I am enormously relieved and happy to be back on British soil," she said in a statement. "It has been an unimaginable nightmare."

Orobator's mother, Jane, told reporters Friday she is overjoyed by her daughter's return. "I can't express how happy I am. I knew she would come home."

She said she hopes the British government will work toward her daughter's final release.

Police say they found 1.5 pounds of heroin in 68 capsules on Orobator's body when she was arrested in August 2008 as she traveled to Australia.

Heroin trafficking is punishable by death in Laos. Orobator was spared because the law does not allow the execution of pregnant women and she was already pregnant at the time of sentencing. She is due to give birth in weeks.

"To call the Lao legal proceedings a kangaroo court would be an offense to the Kangaroo family," said Clive Stafford Smith, director of the human rights charity Reprieve that worked on the case. "How can we justify throwing someone in prison when we don't even know the basic facts?"

He said Reprieve would take legal action against the British government next week unless it challenges Orobator's sentence.