A company run by a senior UKIP politician is selling what appears to be industrial-strength bleach as a health product, with instructions for users to put a few drops of it in drinks or use it with water as mouthwash.

Andrew Haigh, who was appointed UKIP’s national organiser for Wales in 2015, has, according to the website of his company Vitalox, been supplying “Aerobic Oxygen” since 1998. Its leaflet describes it as “good for you” and “the healthier element” – it says it "harness[es] the powerful healing properties of oxygen for use within the body".

However, a chemist who tested the product told BuzzFeed News it’s “reasonable to say it’s sodium chlorite or something similar”, based on the tests he carried out. Sodium chlorite is a powerful corrosive alkali used in several industrial processes, including paper-bleaching.

The Food Standards Agency has in the past warned that sodium chlorite is being sold as a treatment for various diseases under the name Miracle Mineral Solution or MMS, which it described as “equivalent to industrial-strength bleach”.

In 2015, Haigh also ran for the seat of Aberconwy for UKIP, where he came fourth, with 11% of the vote, behind the winner, Tory Guto Bebb.