Doctors are still being paid cash for not referring people for urgent cancer tests, an investigation has found.
Last September, Pulse magazine revealed that Clinical Commissioning Groups (CCGs) were offering rewards to cut the number of people referred to hospitals for key scans and checks.
It has now emerged that, despite reviewing their policies, at least one CCG is still offering rewards to stop referrals, due to what it considers are high numbers of people undergoing cancer checks.
First hospital appointments for cancer should occur within two weeks of a GP suspecting the disease.
Some CCGs have argued the incentives represented no conflict of interest for doctors and said they were cutting the huge variation between practices over referral rates.
Guidance from the General Medical Council (GMC) says doctors must not accept any "inducement, gift or hospitality" that affects or could be seen to affect the way a doctor treats or refers patients.
In the new investigation, Pulse found that GPs are still receiving payments to reduce cancer referrals to hospital.
NHS Lambeth CCG has reviewed its incentives scheme but decided not to change it after a rise in referrals.
The scheme offers payments for practices moving towards the average 2014/15 CCG referral rate per 1,000 patients.
An NHS Lambeth CCG spokesman told Pulse: "In light of recent publicity, it became apparent that the objectives of our work on referral practice may have been misinterpreted. Therefore the CCG took the decision to review the scheme.
'The outcome of this review showed that between April and September 2015, our two-week pathway for cancer referrals had increased by 13% compared to the same period last year.
"Therefore we are not proposing any in-year changes to the scheme."
The spokesman added that the CCG "wants to, and continues to, actively promote good referral practice".
In North East Lincolnshire, an average practice currently receives an incentive of over £6,000 for reducing outpatient referrals to the same level as the 25% of practices with lowest rates in the previous financial year, Pulse said.
Its overall referral figures include those for patients to be seen for suspected cancer within two weeks.
The CCG said it "has not changed the scheme however it has reviewed various concerns raised following the article by Pulse about the potential for unintended adverse impacts" and that "concerns raised in and following the article would be taken into account when taking decisions on any future incentive schemes".
Dr Peter Melton, CCG clinical lead, said: "The result of that review has been that we have been able to provide assurance that those concerns are not being seen in practice within North East Lincolnshire."
An NHS England spokesperson told Pulse: 'Nice (the National Institute for Health and Care Excellence) has set out evidence-based guidelines for when patients should be referred, and no CCG incentive scheme should in anyway cut across that.
"We have contacted each of the CCGs mentioned to ensure this has been clearly communicated to all practices and will continue to monitor the situation."