In August 2017, West Mercia Police and Police and Crime Commissioner John Campion sold the registration number AB 1 to former Chief Constable Paul West.
He had been the last person to use the plate on his official car before it was retired in 2011 due to safety concerns, the same year he left the role.
Mr Campion explained that the plate was unlikely to be used again and that selling it would help raise funds to support community policing.
Although AB 1 was initially entered into an auction with Brightwells, it was withdrawn and sold privately to Mr West.
Angela Banh, marketing manager at Regtransfers, said she was surprised the sale did not go to auction and that the reported price was only £160,000.
She estimated its value at around £175,000 but believed it could have sold for significantly more, possibly as much as half a million pounds, had it gone to public auction.
During a radio interview, Mr West did not confirm or deny the amount he paid, and the Police and Crime Commissioner declined to join the conversation.
BBC presenter Elliott Webb commented that it seemed the plate had been sold for far less than its potential worth.
A BBC source told Regtransfers that the amount paid was officially confirmed as £160,000.
Many accused the West Mercia Police of short-changing the public, and depriving the force of potentially more funds.
An anonymous businessman said he would have been prepared to pay in excess of £200,000, had it gone to auction.
