The polygamy hoax that spread from Iraq to Eritrea

When a far fetched story about enforced polygamy in Eritrea began circulating, it captured attention across the continent. But in fact similar stories - all of them false - have cropped up in a number of countries since the beginning of the year.

And in each case, the way hoaxers spread the rumour on social media pretty much identical. Here's how it plays out.

An "official" government document is leaked on social media, bearing a letterhead, or the signature of a supposed dignitary.

It reads - and we're paraphrasing here - "Due to the recent troubles in our country, we are experiencing a serious shortage of men, and an abundance of woman. Men are now legally required to take at least two wives, and any that fail to do so will face strict punishment." The punishments range from life imprisonment to the death penalty.

When a version of the falsified document appeared in Eritrea this week - as the BBC has already reported - it went viral, and was picked up by a number of news organisations as fact.

The Eritrean government has since been battling to set the story straight, dismissing the document as a fraud, and explaining that polygamy is illegal in the East African nation. It hasn't been able to stop chatter spreading on social media, and a raft of jokes at the countries expense. But more on those later.

Although the rumour about Eritrea went viral, it isn't the first country to be hit by the hoax. At least three other countries have been the subject of the same story, which appears to have begun in Iraq.

A letter mocked up using an official looking letterhead began circulating there early in January, making the same declaration. Because of the country's recent woes, men who failed to take at least two wives would be punished by death, it read.

Of course, it was a hoax as well, but it may not have seemed as absurd a proposition as it did later in other countries. Back in 2011 the BBC reported that Iraqi politicians were considering offering men financial incentives to marry a second wife. Years of conflict have left the country with more than a million war widows, and a shortage of unmarried men. The proposals were never enacted.

Following Iraq, a near-identical hoax document surfaced claiming to be from the government of Sudan. And Arabic news sites suggest a similar letter supposedly from officials in Saudi Arabia was circulated as well - before the story about Eritrea cropped up.

And the rumour about Eritrea? That actually began in Kenya and Nigeria. It was first reported by Kenyan news site Crazy Monday, well known for its focus on gossip stories according to Mathias Muindi from the BBC's media monitoring service. The story was picked up and reported as fact in Nigeria and later South Africa as well.

It spread quickly, and it wasn't long before jokes stared spreading on social networks like WhatsApp and Twitter, mostly involving men from outside the country flocking to Eritrea in the hope of finding multiple wives.