An employee of the Harry Potter studio tour who stole more than £36,935 (NZ$72,000) worth of magical merchandise was caught after colleagues noticed the items accumulating under his desk.

Adam Hill stole Harry Potter merchandise including wands, ties, badges and keyrings from the Warner Brothers Studio stockroom between December 2017 and March 2018, and advertised and sold it on his eBay account, the Crown Prosecution Service (CPS) said in a statement on Friday.

Hill, 35, posted the items from his local post office and later used his company's own post room to distribute the stolen items, the CPS said.

The thefts were discovered after colleagues noticed Harry Potter memorabilia was appearing and disappearing under his desk and reported him to their bosses, the CPS said.

An internal investigation found that Hill had sold 1,040 items of Harry Potter items through his eBay account, and a search of his car revealed 12 parcels of merchandise ready to be posted.

Hertfordshire Police searched Hill's home in St. Neots, Cambridgeshire, England, and seized more themed merchandise, as well as envelopes and packaging, the CPS said.

"In a significant breach of trust, Adam Hill had the audacity to steal thousands of pounds of merchandise from Warner Bros in plain sight of his work colleagues; but they reported him after growing suspicious of the items constantly piling up under his desk," Jan Muller, senior crown prosecutor said in a statement.

"Subsequent scrutiny of Hill's eBay and PayPal accounts revealed orders and payments received for goods which were found packaged up ready to send to buyers, giving him no option but to admit to his crimes," Muller added.

A spokesperson for the Warner Brothers Studio Tour declined to comment on the investigation.

Hill pleaded guilty to theft by employee in November, and was sentenced to 14 months in prison suspended for 18 months and 250 hours of unpaid work on Friday.