Ticketholders for the sell-out Michael Jackson concerts at London's O2 from July should now get their money back.
Fifty shows - due to start on 13 July and set up as his big comeback dates in the UK - sold out rapidly from official ticket sellers.
Fans who bought directly should now get a full refund, although it is a gloomier picture for those who bought from a third party.
If no terms and conditions applied then these buyers have no legal rights.
Anyone who bought tickets directly from the O2, or from agencies connected to the tour should get a refund or possibly an exchange for another event as stated in their terms and conditions.
Tickets bought direct should stipulate a refund in the terms and conditions
Established agencies should also have a refund policy in their terms and conditions
No legal rights exist for those buying from private sellers
Ticketholders should check their confirmation e-mail for the name of the ticketing company through which the tickets were bought. This shows who they should make their claim to. Most actual tickets had not yet been sent out.
A representative for concert organiser AEG Live said an announcement would be made in the next few days.
"At this time our thoughts are with Michael's children, family and friends. We will announce ticketing details in due course."
A statement from official ticket seller Ticketmaster said: "Ticketmaster is aware of the news relating to Michael Jackson. We have no official information at this stage.
"As soon as we have any information we will immediately contact all customers who have booked tickets through Ticketmaster or GET ME IN!"
However the terms and conditions on its website state that a refund of the ticket and any booking fee should be given if an event is cancelled.
But Tony Northcott, of the Trading Standards Institute, said that the picture was a little more opaque for those buying from elsewhere.
If these tickets were sold on by established agencies then terms and conditions offering a refund for cancellation should again be in place.
Examples of such refunds came with cancellations of shows such as when Amy Winehouse pulled out of a tour in 2007.
But if tickets were bought from private sellers on the internet or in person then no terms and conditions are stipulated and so the buyer does not have any set legal rights.
The concerts were sold out extremely quickly
In this case, the best ticketholders can hope for is a friendly agreement with the seller to be handed their money back. The seller could then apply for their money from whomever they bought the tickets from.
Ticket exchange business Seatwave.com have announced that it will refund any tickets bought through its website.
"We are all saddened by the news of Michael Jackson's death. All customers who purchased tickets for his O2 shows from Seatwave are covered by our TicketCover guarantee and will get a full refund," said chief executive Joe Cohen.
"We advise customers to use the website rather than our phone lines to obtain this information."
The auction website eBay is advising people who have bought tickets on the site to contact the sellers to ask for a refund. If they bought using Paypal, they can get their money back if the purchase was made during the last 45 days.
It said it was working to remove live auctions of Jackson tickets from its site, although hundreds remained on the site during Friday morning.
"Any existing bids will be cancelled," a spokeswoman said.
Anyone who spent more than £100 on tickets using their credit card, or often a Visa or Mastercard debit card, can apply to their card provider for compensation if all else fails.
Mr Northcott warned that previous experience suggested that some websites that "promised" tickets to fans for a fee could now disappear.
Last summer saw a spate of incidents where unofficial ticket agencies failed to deliver tickets to music fans.
Graham Burns, of the Association of Secondary Ticket Agents, said the association had drawn up a code of conduct for legitimate agents which included a refund policy.
Some large tour operators sold package deals including a ticket, hotel and transport. Once they have received refunds from promoters, they will pass them onto consumers.
Thomson Experience said that it expected many customers would replace their Jackson tickets with tickets to other West End shows.
Tickets for the London shows, promoted by AEG Live, sold at at a rate of 11 per second, 657 per minute and nearly 40,000 an hour.
Fans from as far afield as Japan, Belgium and Dubai queued to purchase their tickets, priced at between £50 and £75. The latest issue of tickets went on sale on Monday. Some 800,000 tickets had been sold.
The concerts were also set to be an enormous corporate event, with Swarovski crystals having recently announced they were teaming up with the star.
Corporate tickets - called the Thriller Package - were on sale for up to £790 and included a champagne reception, seats close to the front and an after-show party.
Dave Newton, of WeGotTickets, said that the Jackson shows' turnover represented a significant chunk of the annual turnover of live gigs in the UK. Refunds would also cost agencies to administer.
"We have not seen anything like this before," he said.
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