A group of fishers has been caught fishing illegally on the Macquarie River near Narromine and issued fines totalling more than $5,000.

The Department of Primary Industries (DPI) said fisheries officers recently found a camp being used by seven fishers downstream of Narromine.

The DPI's Tony Andrews said a number of offences were uncovered including the use of 41 unattended lines, possession of fish illegally taken and the use of 21 live finfish as lure or bait.

"Seven people were apprehended by fisheries officers and admitted to the offences when interviewed," said Mr Andrews.

"Officers seized 41 set lines, 2 gaffs (a type of hooked pole) and 31 European carp.

"[The fines totalled] $5,200 and a number of written cautions were issued to the members of the camp."

The DPI said a maximum of two attended fishing lines are allowed in inland waters and they must be within 50 metres in the line of sight of the fisher.

Mr Andrews said people found to be illegally fishing should take this as a warning.

"Fisheries officers are targeted in their operations and if you are doing the wrong thing it is only a matter of time until you are caught."