Widespread thefts of diesel have been reported across the Western Australian Wheatbelt as thieves continue to take advantage of trusting producers.

Inspector Mick Walker, Wheatbelt District office, said more than 400 litres of diesel was reported stolen from the Cunderdin area last week.

"Fuel theft is increasing slightly as prices continue to rise," Insp Walker said.

"Farmers need to be particuarly vigilant and report any suspicious movement of vehicles, especially if they are carrying fuel tanks or drums."

Thieves were taking any opportunity to steal fuel out of tanks on farms and even from vehicles on the side of roads.

"We encourage farmers to put locks on their tanks and not to leave large vehicles full of fuel in remote areas," Insp Walker said.

"The best thing farmers can do is not give people the opportunity to steal their fuel."

Inspector Walker also recommended farmers did not order more fuel than they needed.

"It is best not to have excessive amounts of fuel lying around the property," he said.

"Farmers should also try and keep fuel from areas where it can be observed by potential thieves."

WAFarmers wants many of the 64 new police who graduated last week to be allocated to rural and regional WA.

WAFarmers president Mike Norton said he hoped a fair proportion of the latest Police Officers would be allocated to rural WA, given indications that rural crime, such as fuel and high value consumable item theft, was on the rise.