A supermarket chain has incurred the wrath of Belgium’s most famous monks after selling their celebrated Trappist beer at an unholy price.

The brewing brothers of the Abbey of Saint Sixtus in Westvleteren in Flanders have strict rules governing the sale of their beers, which appear to have been broken by the Jan Linders chain.

The monks, renowned for the dark 10.2 percent Westvletern X11, refuse to sell their three iconic beers to shops and only brew enough to cover their annual expenses.

The beer is sold by the glass at a bar opposite the 19th Century Cistercian Abbey, which warns prospective buyers they will need a “lot of patience and a bit of luck” to buy a crate.

Only people blessed enough to get through on a dedicated phone line can buy beers including the “twelve”, which is regularly voted the best in the world.

A buyer can reserve a maximum of two crates of 24 bottles for between £31 to £39 a crate. They must pick them up at the abbey gate at an agreed date and time after handing over their car numberplate.