Image copyright Athena Image caption John, Matthew and Jean Hargreaves appeared before Merthyr Crown Court on Friday

A father and son who sold teeth whitener with 110 times the legal limit of hydrogen peroxide, have been jailed.

Matthew and John Hargreaves admitted participating in a fraudulent business, while Jean Hargreaves admitted engaging in an unfair commercial practice.

The trio, from Knutsford, Cheshire, sold the product at the Royal Welsh Show in Builth Wells, Powys, in 2013.

The two men got 18 months in prison and Jean Hargreaves received a six month sentence, suspended for two years.

Sentencing the three, Judge Philip Harris-Jenkins said: "You put personal greed ahead of public safety."

Merthyr Crown Court heard the family made £3.4m from the venture - a figure disputed by defence counsel - with John Hargreaves, 69, playing a leading role until handing over to his son, Matthew, 44, in 2010.

Jean Hargreaves, 71, was said to have played a lesser role than her husband and son.

Powys council's trading standards team launched a three-year, £400,000 investigation into the three after tests on the products at the agricultural show showed the hydrogen peroxide levels were "harmful".

The council's investigations led them to 30 victims across the UK, including one who required hospital treatment.

Investigators found the three had tried to sell the whitener at about 150 venues, including shopping centre, as well as online.

The council said numerous unsubstantiated and false claims were discovered on banners at the Royal Welsh Show, including claims the product was "ideal for any age group" and was "used by leading dentists throughout the UK and Europe".

Image copyright Powys council

The product was 11% hydrogen peroxide. It is legal for anyone to treat themselves with an over-the-counter kit, provided it contains less than 0.1% hydrogen peroxide. A dentist can legally use 6%.

Excessive levels of the chemical compound can cause blistering, burns and other damage.

Prosecutor Mark Wyeth QC said the whitening had "harmful levels of hydrogen peroxide, thereby putting at risk the health of anybody who happened to buy this product".

The court heard the family would change the name of the company they operated under and dissolve businesses in order to evade unhappy customers and the authorities.

The father and son's involvement stretched from 2007 to 2015, while Jean Hargreaves' crime was carried out between 2013 and 2015.

The family have refused to disclose where the whitener was manufactured, as well as the supply chain.

Media playback is unsupported on your device Media caption Kathleen Haigh told BBC's Fake Britain programme she was still experiencing the ill-effects of using the products

Mr Wyeth said since the broadcast of BBC's Fake Britain programme featuring the Hargreaves was broadcast, Walsall council had discovered Matthew Hargreaves was still trading in teeth whitening products.

The court heard John Hargreaves, who accepted a caution in 2007 for selling similar teeth whitening products at Manchester Airport, used his wife to "provide a layer of protection against investigation".

It was also told the two men had aspirations of producing even stronger products with hydrogen peroxide content of 22-38%.

Sukhdev Garcha, defending Matthew Hargreaves, said he played a subordinate role but had accepted his actions and expressed remorse.

Representing John Hargreaves, Amos Waldman said: "His involvement reduced towards the end - he effectively retired. He accepts entirely he was dishonest."

Anthony Barraclough, defending Jean Hargreaves, said: "This lady would never have condoned the sale of dangerous chemicals. She has been devastated by all of this."

Jean Hargreaves was disqualified from being a company director for five years while the two men were banned for 10 years.