There are an estimated 10,000 people in the United States who identify themselves with the community of Irish Travellers, descended from a group of families that crossed the Atlantic as early as the 1830s.

Although the community has always been an insular and secretive one, US Travellers have recently allowed outsiders a peek inside their world through documentaries and reality television shows like 'My Big Fat Gypsy Wedding,' reports

Paul Connolly, a filmmaker whose documentary “Travellers in America: A Secret Society" will air on TV3 in September, has revealed some of the customs of the secretive group.

A clip of the TV3 show has a woman from the community explaining their traditions regarding marriage saying that it's fine for a 13-year-old girl to have sex with her "husband" as long as "she's started her cycles."

Said Connolly: “We’d heard a lot about this but one of the biggest things was trying to cut through the line of fact and fiction.”

"What we discovered is that the girls are matched with older men at the age of six or seven – but there’s nothing untoward here at this stage. It’s all to do with legacy – if you marry into another rich family then pride of place in the town will stay with you for years to come.

"So at six or seven, families just say ‘they might make a good pair’. Then, at the ages of thirteen or fourteen they will have a marriage ceremony, but they won’t in fact be married.

"The controversial aspect though is that these thirteen- or fourteen-year-old girls will be in a mock marriage with 22- or 23-year-old men."

When Connolly attempted to make contact with the community of Murphy Village in South Carolina, he found it difficult at first, but he and two members of the Navan Traveller Workshop were able to "break the ice" with community locals.

However, he said he was "high-tailed out by a couple of vans" when he went to focus on the Oakhaven community in Tennessee, so the presenter made an appearance on a local morning TV news show to explain what he wanted to do and then soon heard he was being invited to visit the area. After filming began he found many similar traditions between the two groups.

"What was amazing was that same customs had been preserved. They still speak Cant – but it’s a Gaelic-based Cant, unlike here – and they have the same traditions about money, about male and female roles in the community.

“However,” he says, “what most people find interesting about them is that they are incredibly, incredibly wealthy."

Connolly said the men work at “trades – tarmacing, roofing and so on” but “most of the income comes from insurance."

"It’s just very, very clever. In America, there’s a clause which allows you to insure anyone with a blood connection – and as they have intermarried for generations, there’s a likelihood there will be a blood connection.

"So they’ve worked out a way of profiting from this, and that, according to the Travellers I’ve spoken to, is how they make their money and how they’re so wealthy. Some of the more morbid characters we came across referred to it as ‘Death Watch’.

"It’s a typical part of their lifestyle. As a wedding present someone will say ‘you can take a policy out on me!’ – so it’s a loophole that hasn’t been closed, I guess.

Connolly says that the couples will marry formally once the girl is of legal age, but that the couples are allowed by some families to have sex before that point.

He added that his overall impression of the Travellers was one of a welcoming people who "haven't fully assimilated into our world."

Here’s a clip from “My Big Fat Gypsy Wedding”: