An Indonesian court has upheld the death sentence handed down to a 56-year-old British woman found guilty of trafficking cocaine into Bali.

A spokesman said the Bali high court, sitting in the island's capital Denpasar, had confirmed the death sentence given to Lindsay Sandiford in January, which had been a shock verdict after prosecutors recommended 15 years' jail.

The court "decided to uphold the decision of the Denpasar district court", spokesman Makkasau said.

Indonesian police say she was at the centre of a drug ring involving three other Britons after a drugs haul worth $2.4 million was found in her suitcase as she arrived on a flight from Bangkok last May.

Sandiford can now appeal to Indonesia's supreme court.

If that appeal is rejected, she can seek a judicial review of the decision from the same court. After that, only the president can grant her a reprieve.

Sandiford had argued she was forced into transporting the 4.79 kilograms of cocaine in order to protect her children whose safety was at stake.

The court ruled she had not admitted her crime and had damaged Indonesia's hardline stance on drugs as well as Bali's reputation as a tourism destination.

It rejected the argument that Sandiford had acted to protect her children and said there were "no mitigating circumstances" to allow for leniency.

Britain raised objections at the time of her sentencing, with junior foreign minister Hugo Swire saying: "We strongly object to the death penalty."

London also raised concerns in February that Indonesian authorities mistreated Sandiford in prison, alleging in a submission to the Denpasar district court she was threatened with a gun and deprived of sleep.

Three other Britons arrested in connection with the case received lighter sentences.

AFP