The conviction in the UK of Faryadi Zardad for a campaign of hostage-taking and torture in Afghanistan was achieved following an investigation described as "one of the most difficult... ever undertaken" by anti-terrorism officers.
The Afghan warlord had denied all charges against him
Scotland Yard's Anti-Terrorist Branch began investigating Zardad in March 2001, after BBC's Newsnight programme tracked him down to a home in south London.
The police investigation involved trips to Afghanistan by detectives to gather witness accounts and documentary evidence, and witness testimonies given to court by satellite video-link - a UK first.
"It was a huge challenge, in the prevailing circumstances in Afghanistan, to investigate and find evidence to the standard demanded by the British courts," said Deputy Assistant Commissioner Peter Clarke, the national co-ordinator of terrorist investigations.
"Today's verdict shows what can be achieved, and that the UK is not a safe haven for people like Zardad."
Zardad is the first person to be tried in the UK under laws in the Criminal Justice Act, which allow alleged torturers to be tried regardless of where their crimes are said to have taken place.
The police investigation and subsequent court cases - Zardad was convicted at a retrial after a jury last year failed to agree a verdict - cost at least £3m.
Director of Public Prosecutions Ken Macdonald said: "Our lawyers have worked relentlessly to prepare this case - including visits
to Afghanistan - and have overcome the difficulties of proving crimes committed in another country over 10 years ago."
The Old Bailey jury heard that the former mujahideen commander had controlled a key road between the Afghan capital Kabul and Jalalabad.
Military checkpoints run by his men were the sites of numerous offences of hostage-taking and torture between December 1991 and 1996.
Witnesses described being robbed at gunpoint, and beatings with rifle butts, sticks and bicycle chains.
Many said they were illegally imprisoned and tortured for several months.
Some hostages were exchanged for members of Zardad's group that had been captured by rival factions; ransom demands were issued to relatives for others.
After the Taleban took power, Zardad entered the UK in 1998 seeking political asylum.
"Innocent Afghanis and workers from international aid agencies were tortured and robbed by Zardad," DAC Clarke said.
"His victims were humiliated, frightened and intimidated. They had suffered extreme violence at his hands and were fearful of the consequences of speaking out.
"We had to find witnesses in remote parts of Afghanistan and give them the confidence to come forward to give evidence in a British court.
"The fact that they did so is testament to their courage and to the skill of the police officers who supported them."