A British man working in Afghanistan as an adviser to the Afghan government has been shot dead in the capital, Kabul.
Mr MacQueen had been due to leave Kabul (photo by Ash Sweeting)
Steven MacQueen was killed late on Monday while driving alone in his car on a main road in the city centre.
Police say the 41-year-old - born in Selkirk, Scotland - died after his car was shot at from another vehicle, and the unidentified attackers escaped.
Mr MacQueen had been due to leave Afghanistan within days to be reunited with his pregnant American fiancee.
The couple's first child is expected to be born within weeks.
The Foreign Office has informed his next of kin of his death, an embassy spokesman said.
Mr MacQueen had been working for Afghanistan's ministry of rural rehabilitation and development, which said it was "devastated" at the news.
He was working on a rural credit scheme, one of its aims being to reduce the dependence of farmers on growing opium.
It is still not clear why he was targeted.
The BBC's Andrew North in Kabul has been to the scene of the shooting and counted three bullet holes in a metal gate nearby.
Two Afghan guards, one from the Dutch embassy and another from the nearby United Nations guest house, are both reported to have been taken away for questioning by police, although they are not believed to be directly involved.
Mr MacQueen was a well-known figure in the development community in Kabul, and was due to leave Afghanistan later this week after finishing his contract.
Our correspondent says the shooting is bound to lead to a reassessment of security in Kabul, after months of relative calm.
The UN estimates that there are around 2,000 Westerners working in Afghanistan as diplomats or aid workers.
Most are based in Kabul, which is generally considered to be safer than other parts of the country.
A Kabul car bomb killed six last August
It is patrolled by thousands of Nato-led peacekeepers, but, even so, Westerners have been caught up in violence in the capital.
An American woman was killed in a suicide bomb attack in the city in October, the same month as three United Nations workers were kidnapped. They were released unharmed in November.
Last August a car bomb went off outside the offices of an American security firm in the city. At least three Americans and three Afghans died in the blast, which the Taleban said it carried out.
In May 2004 two Westerners were stabbed and stoned to death in the old part of the city.