A fundamental part of a wedding celebration for many Nigerians is under threat.

The moment is always eagerly anticipated.

The bride and groom start dancing and the guests step forward brandishing large wads of cash.

As the band plays, they start flinging – or, as it is referred to here, “spraying” – the money, one note at a time, in the air and at the happy couple.

The cash spins to the ground and once scooped up, it can be used by the newlyweds to buy a present or towards paying for the party.

“I can’t imagine attending an event and not spraying money. It will look as if you don’t appreciate and love those celebrating,” one guest at a recent wedding in the northern Nigerian city of Kano tells the BBC.

The groom at that wedding, who would only talk to the BBC on condition of anonymity as he now fears getting into trouble, says he continues to look at the videos and pictures of the spraying “because I loved it”.

The problem is that the authorities have started to crack down on spraying money. Some prominent personalities have even been sent to prison.

It may appear to be an ostentatious yet essentially innocuous act but in Nigeria this much-loved institution is a crime: the abuse of the country’s currency, the naira.

The 2007 Central Bank of Nigeria Act is unambiguous. “For the avoidance of doubt,” it says, “spraying of, dancing or [marching] on the naira or any note issued by the Bank during social occasions or otherwise howsoever shall constitute an abuse”.

The punishment is no less than six months in prison or a 50,000 naira fine ($36; £29), or both. The fine was set in 2007 and the figure has not been adjusted for inflation.

On the statute books for 17 years, this clause was largely ignored until recently when the elite anti-crime agency, the Economic and Financial Crimes Commission (EFCC), said it was leading a drive against "all forms of naira abuse".

Officials have said that spraying naira shows a lack of respect to one of the country's most important symbols.

Some analysts say that the recently appointed EFCC boss, Ola Olukoyede, has been trying to make a name for himself through this clampdown.

In February, actress Oluwadarasimi Omoseyin was sentenced to six months for spraying and stepping on new naira notes.

Last month, one of Nigeria's most popular celebrities, a transgender woman known as Bobrisky pleaded guilty to four counts of abusing the currency and is currently serving her sentence.

Bobrisky was seen in videos spraying notes in the air in a sign of appreciation at various social events.

A short time later socialite and businessman Cubana Chief Priest became the latest high-profile figure to be charged with abusing banknotes. He settled the case out of court.

The agency says 200 people across the country face prosecution, while 24 people have already been convicted.

As a consequence of its sweep, people have been bombarding the EFCC’s social media accounts with videos of people spraying cash, but the agency says it cannot go after everyone.

It is hard to imagine that a practice that goes back decades could be stamped out just like that.

Historian Prof Tijjani Naniya traces Nigerians’ love affair with spraying to the 1940s when he says families saw it as a way of giving financial assistance to a newly married couple.

“At first people didn’t spray notes but the groom would be seated while people would come up to him and put money in his pocket,” he tells the BBC.

“It was their way of helping him… as he begins a new life that comes with expenses.

“It was later that it evolved to spraying while the couple dance. That way the sprayer shows his status as a wealthy person and people compete to become the most recognised by spraying more money.”

The professor says it will be difficult for Nigerians to totally stop the habit but believes the current tough economic situation has already greatly reduced it.

“Spraying notes was all about [showing off] and as the economy nosedived, a lot of people have stopped.”

However, the practice has expanded beyond weddings.

Hadiza Usman, who at a recent birthday celebration was sprayed with money, says she cannot imagine a Nigerian social event without it.

“We grow up seeing our parents spraying notes at events and it has become part of our cultures all over Nigeria,” she says.

At the same time there are some like Usman Idris who have never sprayed and do not like the concept.

“I hate the idea because it gives the illusion that our country is wealthy when in fact there are more poor people around.

“Over the years Islamic clerics have warned against it and fewer Muslims are spraying money at events today.”

Some clerics have described the practice as extravagant and say that giving to charity is a better option. In an effort to discourage spraying, some have said that the sprayed cash will turn into snakes to bite the sprayer in the grave after they die.

Public affairs analyst Sani Bala thinks the current clampdown on naira spraying will not have the desired effect.

“I think for naira spraying to stop totally, the government needs to start from the top because we have seen governors and ministers spraying money with no repercussions at all,” he says.

“Secondly I also feel the timing is wrong as most Nigerians battle with more pressing issues at the moment.”

But there has been a small, though noticeable, shift in behaviour in some places.

Sprayers are now asking for the largesse not to be filmed or photographed, or sometimes more subtly putting money in the pockets of the groom.

While for Nigeria's super-wealthy elite, there is another option - they can continue to spray dollars, pounds or euros without fear of prosecution, as this law only covers the naira.