Since the murder of Pakistan coach Bob Woolmer, there has been much speculation, still unsubstantiated, that the motive for his killing was to prevent him disclosing match-fixing in cricket.
So how does match-fixing work? And is illegal betting usually on the actual outcome of matches?
Cricket is a difficult game to fix
If you think match-fixing in cricket is about winning and losing matches and about how illegal bookmakers' syndicates bribe players or teams to throw away games, think again.
The fact is simple: fixing in cricket does not necessarily have to do with winning and losing games.
It is a notion that the ill-informed spread that teams lose matches deliberately. It is never easy to fix matches since that will need the support of many key players, if not all.
And there is a good chance that officials will figure out when something is too obviously fishy.
It is less difficult for bookmakers to gain access to captains or individual players and bribe them to control the flow of games or under-perform.
In fact, more monies ride on seemingly innocuous things - the decision of a captain on winning the toss, deciding who would bowl first with the new ball or who would take first strike.
Of course, you can make big money if you know stuff like the timing of declaration of an innings or if a captain would impose the follow-on or not.
Betting on such events is called spot betting and, by some accounts, more than two-thirds of the bets in the illegal market are on such events.
One of the oldest allegations of fixing (spot betting actually) is from 1979.
Arif Ali Abbasi, a former Pakistan Cricket Board official told a commission investigating match fixing in cricket in Pakistan in 2000 that the Pakistan captain Asif Iqbal had told his Indian counterpart GR Viswanath at Eden Gardens, Calcutta, that the Indian captain had won the toss even before the coin fell to the ground.
Iqbal has always maintained his innocence and pointed out that nothing was proven.
There are rumours of Bob Woolmer's murder being linked to cricket betting
You may wonder why a player - well paid and aware of his responsibility towards himself, his team, his sport and his nation - would even think of indulging in any form of activity that we commonly call match-fixing.
Of course, the lure of easy money, greed and stupidity can combine to make a player go awfully against the tenets of fair play that cricket embodies.
The late South African captain Hansie Cronje is the only player to have publicly accepted having fixed at least a match.
"It is very hard to explain," he once said. "Sometimes you have to pinch yourself to realise what the position is at the moment.
"I don't know why I did it. I've asked myself the question so many times over and over again. And it's obviously a mistake that I've made. I cannot find one answer that will give me an answer to that one question."
How can a cricketer be involved?
The most common form of involvement is to give out information to bookmakers that they can use to their advantage.
Australian cricketers Mark Waugh and Shane Warne were the first known players to be fined by their national cricket board for having accepted financial consideration in return for inside information.
The Indian police say they have phone recordings to prove that West Indies all-rounder Marlon Samuels is among the latest to join the list of players who have give out team information to bookmakers. Samuels denies this.
A player can also under-perform or influence others to under-perform in a given match.
The best example of that is Hansie Cronje getting team-mates Hershcelle Gibbs and Henry Williams to under perform in a one-day match in India back in the year 2000.
Both Gibbs and Williams were banned for six months each and fined as well. Pakistan captain Salim Malik's attempt to bribe Australians Warne and Tim May in Pakistan in 1996 is also well documented.
Another way in which a player can be involved is by placing bets.
The most famous case in cricket history is that of Australian players Dennis Lillee and Rodney Marsh taking a 500-1 punt on England turning the tables on their own team to win a Test match in 1981.
Hansie Cronje admitted to having a fixed a match
Of course, even a friendly punt is no longer possible as the player/s can be penalised.
Can someone else from the game be involved with the bookmakers?
There has been at least one reported instance of an umpire also falling in the trap of the bookmakers.
A report by India's top detective agency, the Central Bureau of Investigation (CBI), in 2000 quotes bookmaker Mukesh Gupta as having confessed that he had used a senior Indian umpire to glean information on the pitch during a one-day series against England in 1993.
Umpires Cyril Mitchley and Rudi Koertzen also revealed that they had been made substantial offers in Pakistan and Singapore.
Even a Delhi-based grounds man came under the scanner.
This was after a former Indian test player reportedly told the CBI that he had paid the Delhi grounds man 50,000 rupees ($1,000) for laying out an under-prepared pitch for a Test match against Australia in 1996.
Clearly, there are enormous betting syndicates, perhaps with connections in the underworld, that run the network.
There was a time when it was believed that they were based in Dubai, Karachi, Bombay and Delhi.
But, if the police are to be believed, it does look like there are also networks in Indian cities like Nagpur and Bhopal as well as Lahore in Pakistan and Kuala Lumpur in Malaysia.
Time was when it was easy to track these hubs down because the syndicates would rely on phone landlines. Now with cell phones and other modern forms of communication, it has got tougher for law-enforcers to even track the centres and make preventive arrests.
G Rajaraman is a senior sports journalist with Outlook magazine and is author of Match-fixing: The Enemy Within.