Burglars stole nearly £2 million worth of jewels after smashing through a wall with a sledgehammer during a night-time raid.
Asian gold and diamond necklaces, bracelets, pendants and earrings were snatched during the break-in at a jewellers in Forest Gate, east London.
Scotland Yard have now released CCTV showing the intruders stuffing rucksacks full of looted goods.
Metropolitan Police issued an appeal to trace eight suspects following the burglary on July 10.
Investigators say that three men entered through a narrow hole they bored into the shop's wall while eight others acted as lookouts at Joyalukkas.
Three burglars wearing gloves spent more than three hours inside the shop from 3am, having used a sledgehammer and crowbar to gain entry.
Lookouts scouted the nearby streets the prior day, police said.
CCTV of the break-in showed the suspects wearing hoodies and sprawled out on the shop flaw as they put stolen goods in their bags.
Detective Chief Inspector Andy Pallett said: "This was a meticulously planned and audacious raid on a jewellery shop with £1.8 million of items stolen.
"While we think it only took the suspects around 20 minutes to make the hole, it must have been noisy work and we would appeal for anyone who heard or saw anything suspicious to contact us."
Joyalukkas, one of a cluster of jewellers in Forest Gate, is part of an international chain which describes itself on its website as "the world's favourite jeweller".
Anyone with information should contact Newham CID on 020 8217 5414 or Crimestoppers anonymously on 0800 555 111.