A £25,000 reward is being offered for information that leads to the arrest and conviction of those involved in a robbery at a bank in Quedgeley last week.
The reward has been donated by HSBC, whose branch at the Olympus Centre retail park was ram raided on Friday, October 5, as staff were loading money into the cash machine.
A Nissan Navara was used to force open the main glass door before two men wearing balaclavas entered the building and took around £100,000 cash.
A car matching the description of the vehicle used was found abandoned in Carters Orchard in Quedgeley on Sunday, October 7.
Detective Chief Inspector Marc Flannery said: "We’re hoping this money may convince someone to come forward who was reluctant before.
"These offenders need to be stopped before they strike again and possibly hurt someone.
"We’re continuing with a number of forensic and other inquiries but still need information from the public. Please think back to that morning and call us if you can help. No matter how small a detail you think it is we want to hear it."
Officers are still particularly keen to speak to customers who tried to use the ATM, which was out of service, between 9am and 9.25am.
Police would also like to hear from anyone who saw the green, double cab Nissan Navara (registration number SV03 GVL) in the Carters Orchard area or nearby between 9.20am and 9.30am on the day of the ram raid.
Anyone with information should ring 101, quoting incident 120 of October 5.
Alternatively information can also be given anonymously on 0800 555 111, or via www.crimestoppers-uk.org.