One player in Clash of Clans, the addictive war game app, has spent more than $1 million on in-app purchases to buy his way to the top of the game's league system. The player is believed to be a Saudi. At least, that was the gossip we heard at Engage London, the conference that about 400 social media executives attended this week, hosted by Socialbakers.

Supercell, the Helsinki company that makes Clash of Clans, told us that this is not in fact true. But it's a measure of how robust Supercell's COC business is — it books revenues of $1.5 million a day — that people believe this could be true. Our source heard the rumour from someone at a company that has an app-purchase processing business. (We promised not to name the firm.)

There is, however, some circumstantial evidence that Middle Eastern players are dominating the uppermost league of Clash of Clans. Some of them say they're paying up to $16,000 to get there.

A gif of some Clash of Clans gameplay as shot by "Godson," who runs a YouTube account dedicated to the game. Godson / YouTube

First the context, for those of you who don't play the game. COC involves building a base and then defending it from other players. You can add defences and weaponry to your base either by looting coins from other players or collecting them from mines. But this takes a long time. In order to amass the 5,000 trophies necessary to enter the uppermost "Legends" league within the game, you might have to play intensely — 10 hours a day or more— for maybe two straight years.

Players are incentivized to pay for wall upgrades, gold, elixir, and expensive archer towers, for instance, because if they leave their bases untended in real time other players can come along and attack them while they are away, losing trophies and resources.

At the lowest level, a player can buy 500 gems for £3.99 to use toward in-app purchases. That player may then buy 500,000 gold coins at a cost of 336 gems, so the exchange rate is about 1 gem = 1,488 gold coins. At the highest level, each piece of wall costs 8 million coins, and you need over 200 in total at the highest levels.

There is no limit to how long you can play or how much you can spend. Supercell reportedly gets $1.5 million in revenue per day from Clash of Clans. And high-spenders occasionally become legendary within the game. "Richie Mac," for instance, spent $12,000 on this base, according to "Galadon," who runs a YouTube channel devoted to the game:

Galadon / YouTube The global rankings of COC players are dominated by Middle Eastern players. Here is a screengrab of the first time a player won the 5,000 points necessary to enter the Legend League. The player's name is Shaheen UAE, which suggests United Arab Emirates:

Captain Clash / YouTube

But notice that five of the top 10 players appear to have Middle East links: "Adel," who writes his/her name in Arabic; "Emirates"; "Moo" (another Arabic script user); "love" (Emirates again) and "Styleqtr," whose Arabic lettering and screen name hint at Qatar).

Now, there are reasons to be sceptical that a single player could actually spend as much as $1 million in the game even if he wanted to. It appears to cost "only" about $12,000 to max-out a base, for instance. Other players have calculated maximum spending at $6,620 per base. We heard from one Saudi player on Twitter who claims he spent $16,000:

That still doesn't get you anywhere near $1 million ...

George Yao, the former champion COC player who wen by the name Jorge Yao. Jorge Yao / Twitter ... unless you're playing multiple accounts at the same time. George Yao, who used the screenname "Jorge Yao," did just that to maintain his No.1 status before he went cold turkey and abandoned the game. He was the subject of a New York Times profile in 2013 that described how he maintained his dominance. He played five accounts at a time:

Another wealthy clan member in the United Arab Emirates bought Mr. Yao three iPads to make this feasible — but even then, it was feasible only in the technical sense. At one point, he was bringing five iPads into the shower with him, each wrapped in a plastic bag, so that none of his accounts would go inactive.

So, clearly, there are some high-spending Arabs who are addicted to Clash of the Clans. The only open question is just how much they're spending on their habits.