The charity watchdog is investigating after a faith healer allegedly offered £91 "plague protection kits" for sale to protect people from the coronavirus pandemic.
The Charity Commission opened a case after Bishop Climate Wiseman said the small bottle of oil and piece of red yarn would shield his followers from the deadly virus.
In a blog post, the head of the Kingdom Church in Camberwell, south London, claimed his concoction of cedar wood, hyssop and scarlet yarn acts as "an invisible barrier to the powers of darkness".
Bishop Wiseman said the church, which is a registered charity, had sold more than 1,000 of the kits, which were reportedly originally priced at £91.
The link to buy them has since been deactivated following criticism from Southwark Council.
A National Secular Society spokesman welcomed the commission's response but called for reform of charity law.
The plague protection kit is one of many anointing oils offered by Bishop Wiseman for a range of problems, including oil for peace, unlimited success oil and anointing oil for good marriages.
On the Kingdom Church's website, it claims thousands of people have been healed from "all sorts" of sickness and disease since it was founded in 2005.
Bishop Wiseman has previously insisted the church is not selling the kits and that the price tag was just to cover the cost of the ingredients, yarn and postage and packaging.
He said his church was not telling people to ignore the Government's advice, adding: