Why do people collect celebrity underwear?
Celebrity underwear has long attracted interest - and big bucks - with garments once owned or worn by the likes of Ed Sheeran, Kelly Brook and Dame Helen Mirren a big attraction at auctions.
Buyers have also snapped up smalls once sported by Queen Victoria and Madonna - and even Hitler's companion Eva Braun.
So just what is the appeal of the undergarments of the rich and famous?
City University of London's Prof Chris Rojek, a sociologist who is an expert in the study of celebrity, says it comes down to people wanting find a way to get closer to someone they will never meet.
"The audience, or some sections of them, want a relationship of perceived intimacy with the celebrity," he said.
"They are never going to meet them or see their underwear, but if they own them (their undergarments), they feel closer than they would otherwise."
Celebrities haven't been shy in donating their underwear for a good cause.
As well as Sheeran and Brook, Fearne Cotton and England goalkeeper Joe Hart were among those to donate underwear in aid of a breast cancer charity.
While Mirren, Emma Thompson, Jarvis Cocker and Katie Price have also donated pants in a bid to help destitute asylum seekers.
And Rojek believes it is understandable there's a market for these garments.
He says those who buy them want to "acquire some of the glamour of the celebrity, but also to feel that they are, in some sense, in touch with the people who they will never meet".
"I think it is normal for people to want to own something where they feel particularly close to someone," Prof Rojek said.
"When your parents die you want to keep things to feel close to them.
"Celebrities are virtual family to some people."
Specialist fashion auctioneer Kerry Taylor has sold a number of high-profile undergarments, including a corset and knickers worn by Madonna.
"I don't think the fact that it is underwear is a major feature," she said.
"The collectors just want a 'relic' of the celebrity."
The history of the garment can be very important to buyers, Ms Taylor added.
"Of course, underwear is quite amusing and someone like Queen Victoria had hundreds of pairs of stockings and lingerie that seem to have come into the public domain over the years.
"[But] Madonna's gold knickers were sold as part of a fabulous Jean Paul Gaultier show outfit with a corset-like bodice with the famous 'conical' breasts.
"These are just as important to a fashion collector - or even more so - than to a Madonna fan."
For some though, collecting undergarments is a way of owning a piece of art.
Burlesque performer Missy Malone has a collection of more than 100 items from the burlesque scene.
She started collecting in about 2004 when she was studying for a degree in costume design at Edinburgh College of Art.
"I was researching period fashion and had a special interest in lingerie and original showgirl-burlesque costumes from the 1940s and 1950s, so started collecting to study the construction and detailing of the pieces," she said.
"I have carried on collecting over the last 13 years and my full-time career as an international burlesque performer has really allowed me access to some very special pieces from my own industry.
"I adore original stage costumes as I love seeing how they work, the wear and tear, makeup stains, names written inside and knowing that these performers sat and mended their pieces just like I do with mine today," she said.
"I know how much blood, sweat and tears go into these things."
Ms Malone, who is originally from Edinburgh and is now based in Cheltenham, says among her favourite pieces is an original Paramount Pictures costume, which she believes is most likely to be a chorus girl dance costume.
"It weighs a tonne and the workmanship in that piece is incredible," she said.
"I also treasure pieces that once belonged to burlesque performers from the 1940-50s. I have a net bra from Blaze Star and a net bra and panties set from Lynne O'Neill.
"These women set the standard and made it possible for women like me to do this job today, and to have a piece of that history is so important to me."
Vintage photographer Neil Kendall has been collecting burlesque items for about 20 years.
His private collection has around 60 items, which he displays in a pop-up museum, and includes stage-worn costumes and undergarments dating from the early 1920s.
Mr Kendall said many of the items were donated by performers. One of his most treasured pieces is an original jewelled underwear set once worn by legendary burlesque performer Tempest Storm, which cost $500 (£400).
"It is part of this incredible legacy to people that have made a career of parading their body on stage," added Mr Kendall, who lives in Chester.
"For me, it is a passion born from burlesque and the artistry and theatricality - from the stagecraft to the costume and underwear that they wore."