By Tim Mansel
BBC World Service
Is European football experiencing an epidemic of match-fixing that is beyond the power of the authorities to control?
Match-fixers considered drugging players, telephone taps suggest
You could easily draw this conclusion from the number of recent arrests - 46 last week in Turkey, 15 in Germany in November - and from the evidence gathered by investigators in Germany's north-western city of Bochum.
They spent much of 2009 listening in on the telephone conversations of a group they believe fixed the outcome of more than 200 football matches across Europe and made millions of euros by betting on them.
The group preyed on the small, the weak, the vulnerable.
And according to police documents, as well as the carrot and stick of bribe and threat, they considered other possibilities, including that of drugging footballers, either with the help of a team doctor or the hotel kitchen staff preparing their food.
Most Germans had probably never heard of Verl (population 25,000), let alone its semi-professional football team - or not until it emerged that the team captain, Patrick Neumann, had accepted a 500-euro bribe to throw a game.
His lawyer said threats, from one of those arrested in November, had left his client with no choice.
Germans are more likely to have heard of Osnabrueck (population 160,000), though probably not for its football club, currently in the German third division.
Many, however, will now be familiar with the name of one of its players in the 2009 season, Marcel Schuon, because of his role in the match-fixing scandal.
A central defender in his mid-twenties, Schuon had shown promise as a teenager, but was probably never going to make it to the top.
Happier days: Schuon (right) marks a victory with the national under-17 side
He also had a gambling habit that by his own admission had run out of control, and by the spring of 2009 he had accumulated "a mountain of debt".
At that point, as Schuon tells it, the owner of the betting shop to whom he owed money suggested a way out of his predicament.
"He wanted a penalty, a red card, or an own goal," he said in a statement to police.
Schuon says he agreed, because he was scared of the man and wanted to "calm him down". But he says he did not act on his promise.
"I realised during the game, that I couldn't influence the game on my own," he says.
The whole Osnabrueck team put in a lacklustre performance and lost to Augsburg 3-0.
Schuon's predicament sheds light on an apparently widespread culture of gambling among footballers - most of the team used to bet, he told the team - and the trouble that can arise when they get into debt.
The man from the betting shop accused by Schuon - one of the 15 arrested in November - denies having encouraged the player to throw the match.
Schuon (centre) was sacked by new club Sandhausen after his confession
"It was the other way round," his lawyer said. "Schuon was so in debt that he approached my client and suggested he fix a game."
In a previous match-fixing case, in 2007, a judge handing down sentences in Frankfurt described the footballers involved as the "small but necessary wheels" in the apparatus of corruption. "We are not dealing with criminals here," he said.
This may be true. Patrick Neumann and Marcel Schuon may not be prosecuted. But they still have good reason to regret their actions.
They've both been sacked by their clubs, and Schuon has spent time in hospital with what his lawyer described as "psychological problems".
The main defendant in the 2007 case, a Malaysian businessman, was given a jail sentence, and jail is what the prosecutors in Bochum will be pressing for when the cases against the suspects arrested in November finally reach court.
Referee Robert Hoyzer was jailed in 2005 for accepting bribes
From what has leaked out from the investigation, we know the police believe the ringleaders to be prominent figures in organised crime.
This is not one gang, but several small groups from Berlin, Nuremberg and the industrial north-west, connected by a mutual interest.
They include one very familiar name - that of Ante Sapina, a Croatian-born gambler, who in 2005 was jailed by a court in Berlin for bribing a German referee, Robert Hoyzer. Hoyzer also served a prison sentence.
But this is not only a German problem. Games were allegedly fixed from Belgium to Turkey - one game is being scrutinised by both German and Turkish police. The bets were placed in Asia with the help of agents based in London.
The bad news for European football is that putting 15 men behind bars doesn't seem to have deterred people who want to fix football matches.
The German football authorities have expressed suspicion over a number of games that have been played since those arrests.
In March, a Swiss club accused one of its own players of involvement in match-fixing, and there were reports of extraordinary movements on the betting on a game in the Italian Serie A, also in March.
Both the German football association, the DFB, and the European governing body, Uefa, have declined to be interviewed by the BBC about any of the allegations.
But Andreas Krannich, a director of Sportradar, a company that monitors betting patterns on all senior football played in Europe on behalf of Uefa, confided an intriguing nugget of information.
He wouldn't name time or place, but said they had spotted such unusual betting patterns on one game that they alerted Uefa shortly before kick-off.
"A Uefa official went to the locker room and told the teams about the suspicious movements," he said. "And it was strange to recognise that several minutes after this, the betting market completely changed direction and the match was played in a normal way."
The fixers, it seems, are still out there.
You can hear a full account of the investigation by Tim Mansel and David Goldblatt on this week's edition of Assignment on the BBC World Service.