Islamabad- A court in Pakistan on Tuesday jailed a British mother-of-three for life for attempting to smuggle 63 kilograms (139 pounds) of heroin out of the country.

Khadija Shah, who is from the central city of Birmingham and of Pakistani descent, was arrested at Islamabad airport in May 2012 when the drugs were found in her luggage.She was convicted and sentenced at a special narcotics court in Rawalpindi, the twin city of Islamabad, according to legal papers seen by AFP. She was also fined 300,000 rupees ($3,000)

Shah, 26, who was six months pregnant when she was arrested, denied the allegations. She gave birth to a daughter in September 2012 while in custody on the drugs charges. Her other children, a five-year-old boy and a four-year-old daughter, have returned to Britain. Her lawyer Shehzad Akbar said she had no idea there were drugs in her luggage and they would appeal. Legal charity Reprieve urged the British government to help.

"This is a terrible outcome for Khadija and her baby Malaika," Maya Foa of Reprieve said in a statement. "As happens in hundreds of cases, she was used as a drugs mule without her knowledge, and yet is facing life in a Pakistani prison."

A spokesman for the British High Commission in Islamabad said they were providing consular support to Shah and her family. Pakistan's war-torn neighbour Afghanistan is the world's largest producer of opium, the raw material for heroin. Efforts to cut production have failed in the 13 years since US-led forces toppled the Taliban regime there. More than 45 percent of Afghanistan's illicit opiates pass through Pakistan on their way to markets in Europe and Asia, according to the UN Office on Drugs and Crime.