At the time of his death, singer Michael Jackson was rehearsing for a 50-date run at the O2 Arena, in London.
The shows, which were due to start on 13 July, were billed as his big comeback and tickets sold out rapidly.
Fans who bought directly from official ticket sellers should now get a full refund, although the picture is less certain for those who bought from a third party.
If no terms and conditions applied then these buyers have no legal rights. Here's the current state of play:
AEG LIVE - concert organiser
"On behalf of the entire AEG organisation we extend our deepest condolences to Michael Jackson's family and friends during this tragic time."
Full ticket refund information and procedures will be released early next week for all Michael Jackson This Is It shows. Fans are advised to hold onto their ticket vouchers/proof of purchase.
EBAY
"The sad news of Michael Jackson's death has left fans of the King of Pop bereft. EBay is committed to ensuring that no buyer is left out of pocket as a result of the unique nature of the event, and will ensure all buyers on the site can receive a full refund for their ticket purchase."
The online retailer will return sales commission to sellers when they refund buyers, eBay said.
SEATWAVE
"We are deeply saddened to hear of the tragic death of Michael Jackson and offer our sincerest condolences to his family, friends and fans. The world has lost a fantastic performing artist.
"At this time, we would like to reassure you that your Michael Jackson ticket purchase is fully covered by our TicketCover guarantee."
LASTMINUTE.COM
"Lastminute.com shares the sadness of many fans worldwide about the death of music legend Michael Jackson
"We are currently working with the event organisers, AEG, who supplied the tickets, and will follow their full ticket refund policy and procedure once they announce it next week.
"We will be proactively contacting all of our affected customers to explain any refund policy once it's been confirmed."
VIAGOGO
"Everyone at viagogo is deeply shocked and saddened at the news that Michael Jackson has passed away. Our thoughts are with his family, friends and fans.
"All Michael Jackson tickets purchased through viagogo will be refunded directly to fans. No forms, no fuss, just refunded.
"We will be in touch with everyone in due course."