People at high risk of developing cancer are being denied a "life-saving" £200 test on the NHS, a charity has said.
Four in five hospitals across England are not testing bowel cancer patients for a condition called Lynch syndrome - a genetic condition which significantly increases a person's risk of the disease.
Testing for the condition can help guide the treatment of current patients but also determine whether or not their families are at increased risk of bowel cancer.
Lynch syndrome is an inherited condition passed down through families - children of people with the condition have a 50/50 chance of developing it.
It has no symptoms but people who have it have a significantly higher risk of developing bowel cancer and other cancers.
The test to identify the condition costs just £200 and is recommended by the National Institute for Health and Care Excellence.
But the UK's leading bowel cancer charity Bowel Cancer UK and Beating Bowel Cancer found that 83% of hospital trusts are not following official guidelines to test all bowel cancer patients at the time of their diagnosis for Lynch syndrome.
The charity received responses to Freedom of Information requests from 153 hospital trusts in England.
It found that among those who do not provide the genetic test for the condition, nine in 10 cited financial reasons as the main barrier.
The charity, which released the findings to mark Bowel Cancer Awareness month in April, said clinical commissioning groups (CCGs) - which commission services in each region of the country - need to "loosen the purse strings" and ensure funding is available for the test.
Deborah Alsina, chief executive of Bowel Cancer UK and Beating Bowel Cancer, said: "Until there is clear local and national leadership and a firm commitment to improve the services for people at high risk of developing bowel cancer, the estimated 175,000 people who carry this inherited faulty gene will continue to fall through the gaps of health bodies such as the NHS and CCGs because they are reluctant to take responsibility.
"At the moment, hospitals are being pushed from pillar to post, with no organisation being held accountable.
"The price of testing for Lynch syndrome is peanuts - only £200 per patient. CCGs need to loosen the purse strings as the price of testing for Lynch syndrome far outweighs the cost of treating bowel cancer patients.
"A lack of funding and resources from CCGs means that hospitals' hands are tied. Until these issues are being addressed, generations of families will continue to be devastated by cancer and lives will be needlessly lost."
An NHS England spokeswoman said: "There are clear NICE guidelines for when it's appropriate to test for Lynch syndrome that we expect NHS providers to follow but the quality of cancer care is always improving and the NHS is catching more cancers early with 7,000 more people surviving cancer compared to just three years ago."