(CNN) -- A pregnant British woman, who was jailed in Laos on drug charges, arrived in London Friday after being handed over to British authorities to serve her sentence at home.
Samantha Orobator with UK ambassador to Laos at Vientiane's Wattay airport on August 6.
Lao authorities had agreed to release Samantha Orobator and John Watson, another Briton jailed on drug charges, after signing a deal with British authorities last week.
The 20-year old was flown from the Lao capital, Vientiane, on Thursday.
In a statement Orobator said: "I am enormously relieved and happy to be back on British soil. It has been an unimaginable nightmare.
"I would like to thank all those who were involved in my return, including various British government officials, for their efforts on my behalf, and for their support. Meanwhile I would be grateful for a little peace as this has been a very traumatic experience both for me, and for my unborn child."
Wearing a white hat and loose trousers, she laughed as she stepped on to the tarmac, along with three travel companions, the British Press Association reported. Uniformed police stood by as she was led into the van taking her to Holloway prison in London.
The British court system will decide the conditions of her sentence.
Her return to the UK comes in time for the birth of her child which is due next month. Watch more about the case »
Orobator was jailed last August after being arrested with about a half-kilogram of heroin at the airport in Vientiane, officials have said. She received a life sentence for drug trafficking.
"The transfer means that Samantha will five birth in the UK, close to her relatives and under UK medical care," Foreign Office minister Chris Bryant said in a written statement.
"This is clearly the best outcome for all -- not least her unborn child," added Bryant, who recently went to Laos to visit Orobator and another Briton in jail there.
The deal to allow the return of Orobator and Watson -- the only Britons held in Laos -- was signed in May, a spokesman for the British Foreign Office said. Normally, that agreement would have to go through parliamentary procedures before passage, the spokesman added.
Though not specific to Orobator's case, the agreement was signed with her in mind, because officials hope she can give birth in Britain.
Her story made international headlines after she became pregnant in jail and her mother pleaded for her release.
The circumstances under which Orobator became pregnant in prison remain unclear.
She told her mother she was not raped and that the father is not a prison official.
A government-run Lao newspaper reported that Orobator said she impregnated herself with sperm from another prisoner.