UPDATE, 5:15 p.m. ET Tuesday: A customer rearranged the letters on the sign outside a Dayton, Ohio, Speedway gas station to say "Free heroin w/ Speedy Rewards," a company spokeswoman said.

>> Watch the news report here

“After approximately 15 minutes, we became aware of the message and removed it immediately,” Speedway communications manager Stefanie Griffith said.

Someone – possibly another customer – notified the clerk about the sign, she said.

The sign originally read:

3¢ OFF PER GALLON W/ SPEEDY REWARDS 

$I OFF NEXT 2PK NEWPORT PURCH

Griffith said the incident was captured on the store’s surveillance cameras, but that it’s against company policy to release it. She did not rule out pursuing charges.

>> See the altered sign here

ORIGINAL STORY: A sign reading "Free heroin w/ Speedy Rewards" at a Dayton Speedway store has prompted the company to investigate the incident.

“It was found on Saturday, Oct. 14, and was immediately removed,” said Speedway spokeswoman Stefanie Griffith. “We apologize to those who may have seen this sign and are currently investigating how this occurred.”

The photo was taken of the sign at the station on the corner of Smithville Road and Huffman Avenue.

Preliminary reports from the Montgomery County Coroner’s Office indicated there have been 512 accidental overdose deaths so far in 2017. It’s not clear how many of those accidental overdose deaths are directly contributed to heroin.

Dayton and Montgomery County have been plagued by heroin-related deaths for several years.