A South Wales Police helicopter was called in as cover
Dyfed-Powys Police have declined to reveal the cost of using a neighbouring force's helicopter while their aircraft was grounded for 13 weeks.
After a BBC Wales News website Freedom of Information (FOI) request, the force said they were exempt from releasing the details under a section of the act.
An air support unit from South Wales Police was called out 11 times to fill in between April and July last year.
The helicopter was grounded while it was fitted with a new gearbox.
The problem was discovered during a routine service and the part was eventually replaced by a company in Northamptonshire.
The helicopter returned to service on 23 July last year, said police.
In its response to an FOI request, the force said: "I can confirm that Dyfed-Powys Police does hold the information requested.
"However, a section 43(2) commercial interests exemption has been applied to it thereby exempting the release of the information."
The force revealed last July that their aircraft had been grounded for "essential" repairs.
Police said it was away being serviced and a helicopter from the neighbouring force was filling in.
A previous police force helicopter crashed near Cross Hands on Christmas Day, 2001, with the crew suffering minor injuries. A replacement was bought for £3m two years later.