Officers were called in last week after the huge haul was swiped from three trucks in Pastures Road in Mexborough.
Filming for the popular Netflix drama, which tells the story of the British Royal Family, is currently taking place around Yorkshire with scenes being shot at nearby stately home Wentworth Woodhouse.
But police say they have exhausted all lines of enquiry in the probe – while show bosses have resigned themselves to seeking replacements for the props, which included a replica Fabergé egg as well as other items of prop jewellery and antique gems.
South Yorkshire police said the case had been shelved after investigators exhausted all lines of inquiry.
A spokesperson said: “Police were called at 4.30pm on Wednesday 16 February following a report of theft from vehicles at Pastures Road, Doncaster.
“It is reported that three vehicles containing props used in film and TV were broken into and a number of items taken.
“Officers investigated the incident but all existing lines of inquiry have now been exhausted. The case has been filed pending any new lines of inquiry.”
The theft is not expected to delay series five of The Crown, which features Imelda Staunton as the Queen and is due to air later this year.
A Netflix spokesperson said: “We can confirm the antiques have been stolen and we hope that they are found and returned safely. Replacements will be sourced; there is no expectation that filming will be held up.”