Vientiane, Laos - A pregnant British national is expected to be transferred from a Lao jail to the United Kingdom on Thursday to serve out a life sentence for drug trafficking, a Lao official said.

"I can say this issue is approaching its solution," Lao Foreign Ministry spokesman Khenthong Nuanthasing said Wednesday.

"I think that by tomorrow we will be able to transfer Samantha Orobator back to the UK to serve her sentence there," Khenthing told the German Press Agency dpa.

Orobator, 20, was sentenced to life imprisonment last month for heroin trafficking in Laos. The maximum penalty for drug trafficking in Laos in capital punishment by firing squad, but Orobator's sentence was commuted to life because she was pregnant.

Orobator was arrested while boarding a plane in Vientiane last August with 680 grams of heroin hidden beneath her clothes.

Her pregnancy prompted an investigation and delayed her trial, as it occurred when she was held in the prison's all-women section.

Orobator later told Lao investigators that she had been impregnated by British national John Watson, who smuggled his sperm to her in a syringe. Watson is also in jail on drug trafficking charges.

The high-profile case prompted Laos and Britain to push through a prison transfer agreement on May 7, and later sign a memorandum of understanding to speed up the process to get Orobator out of Laos before she enters the eighth month of her pregnancy, at which stage plane travel becomes very risky.

The transfer has been delayed by official documentation.

"We expect to finalize the document by this afternoon (Wednesday) and by tomorrow we will be able to transfer her to the UK," Khenthing said.

He added that Watson would be transferred at a later date, while denying the Briton was in poor health.

"From what I've heard she does not have any health problems, but of course a prison in a least-developed country is not the paradise it is in a developed country," said the foreign ministry spokesman.

Little is known about what led Orobator, a Nigerian-born British citizen described by friends as extremely bright with ambitions to become a doctor, to fly to Thailand and then to Laos where she spent five days before her arrest at Wattaya Airport on August 5, 2008.