Claressa Shields: The 'loudmouth American' with a story worth saying

This article contains references to contains references to rape and child abuse. If you have been affected by any of the issues raised, visit BBC Action Line.

"Dirty water ain't gonna stop us putting on those Gucci clothes."

Claressa Shields is walking around her hometown of Flint, Michigan.

Barking dogs are the soundtrack to a stroll down a street that bears the name of the two-time Olympic gold medallist, and undisputed middleweight world boxing champion.

As she walks, Shields, who some regard as the best women's boxer of all time, is shouted congratulations from all sides of the road.

The 28-year-old is a legend in Flint - a city that needs a hero, advocate and spokesperson more than most.

The original home of General Motors, Flint was known as Vehicle City, but as the American motor industry declined, so did the city's fortunes.

Flint's population is now half what it was in its 1960s heyday and, as people have left, their tax dollars followed.

A 2014 cost-cutting decision to switch the city's water supply from Lake Huron to the Flint River - polluted by decades of heavy industry - had disastrous consequences, exposing its people to lead poisoning and turning tap water to various shades of brown and yellow.

The city's drinking water is now judged to be safe, external but the city itself is still not, with violent crime running at nearly four times the United States' national average., external

Shields keeps walking, and talking, as she drops in the Gucci analogy. It could sound flippant if it wasn't entirely in keeping with the American's zealous insistence that her life's low points are to be channelled.

She believes her harrowing history - explained, named, and put out in the open - can help others.

Flint's water crisis was far from Shields' first challenge.

"At first, I thought my purpose was to be a great boxer. But God wanted me to be a great boxer and to tell my story because it's going to save so many lives," she says.

Shields is a natural storyteller. She has the words, the stories, the confidence. In a week filming for BBC Sport's Born to Brawl series, the tales just fall out of her.

She can trash talk with the best in the world - high praise in boxing, a sport which values running your mouth as much as running the show in the ring.

But, unlike a lot of her counterparts in both women's, and men's boxing, her narrative has depth. Unspeakably dark depths.

An extended period of sexual abuse began when Shields was just five years old.

"I've had to work harder than a lot of people to get to where I am," she says. "I don't know people who could have been in the same situations and get to where I've made it to…

"I'm talking about from the age of five, when I was raped as a young girl to, you know, having to deal with all the anger I had from that.

"I had a speech impediment, I couldn't even talk till I was about six and I stuttered till I was nine.

"Flint has built that no-quit attitude in me. I being a kid and this girl chasing me home from school. I ran in the house and my mum was like, 'What's going on">