A Palestinian look-out surveys the Olympic Village

When the terrorists requested a jet to fly them out of Germany, a plan was hatched to lay on a decoy plane filled with a police squad who could overpower them.

But the team felt they were not trained for this task.

Fearing a suicide mission, they pulled out just seconds before two helicopters containing the Palestinians and Israelis landed at the airport.

Even at this late stage, the Germans thought there was only four or five terrorists, rather than eight, and positioned just five snipers at the airport.

When they opened fire on the terrorists, a policeman standing near the tower was killed by a stray bullet.

The programme tells how a sniper and a fleeing helicopter pilot were shot and seriously injured by members of their own side.

Armoured police cars were called in late as reinforcements, and were then caught in traffic as crowds clogged the roads in an effort to see the drama.

Grenade

The terrorists finally killed the athletes by throwing a grenade into one helicopter and firing a round of bullets into the other.

Yet as the shoot-out was happening, a German government spokesman claimed the operation had been a success, prompting "They're free" headlines around the world.

Ankie Spitzer, widow of the murdered Israeli fencing coach Andre, says: "At midnight came the official announcement from a spokesman of the German government who said all the Israelis are safe and all the terrorists are dead."

It was several hours before she learned the awful truth.

The three terrorist survivors were never tried, and were handed over to Libya in exchange for the freedom of hostages when a jet bound for Frankfurt was hijacked seven weeks later.

The documentary alleges the hijack was set up by the German government in collusion with the terrorists.

A police marksman dressed as an athlete

Secret Israeli assassination squads later killed two of the three surviving Munich terrorists, but Jamal Al Gashey is still alive.

Now in hiding in Africa after surviving numerous attempts on his life, he stands by his murderous actions.

"I'm proud of what I did at Munich because it helped the Palestinian cause enormously," he says.

"Before Munich, the world had no idea about our struggle, but on that day, the name of Palestine was repeated all around the world."

Director Kevin Macdonald has made a harrowing and unforgettable film, which won an Oscar for best documentary feature.

"One of the key things that piqued my interest as a film-maker was the morbid connection between sport and murder," says Macdonald.

"In some ways, the Munich massacre was the ultimate transgression - the destruction of an ideal of peace and brotherhood.

"But as we are now only too well aware, the Olympic movement is not as pure as snow, nor was it ever."

Storyville: One Day in September is broadcast on BBC Two on Tuesday, 5 September, at 21.00 BST