Fashion experts have been surprised by the discovery of four bras around 600 years old in an Austrian castle.

The underwear style was thought to be a little over 100 years old as women abandoned tight corsets, but the linen versions unearthed by archaeologists date back to the middle ages, the University of Innsbruck said on Wednesday.

Hilary Davidson, fashion curator at the Museum of London, said one specimen in particular "looks exactly like a [modern] brassiere". The garments were unearthed in 2008, but the discovery was only publicised by an article in the August 2012 issue of BBC History Magazine.

• This article was amended on 19 July 2012. The original said the discovery of four bras that are believed to be around 600 years old was only publicised by a recent BBC history programme. This has been corrected.