Mr Johnson said there would be no further action against his aide as there was "no conclusive evidence".

BBC: Stephen Greenhalgh

Despite claims to the contrary, there is no conclusive evidence that less medical spending results in better or equal long-term health outcomes.

FORBES: Medicare Vouchers Won't Reduce Health Spending

No conclusive evidence, however, to substantiate a clear relationship between the 65-year reduction in the top statutory tax rates and economic growth.

FORBES: Academics Have Spoken, And Obamanomics Is The Path To Slow Growth

The airport said one Jet2 aircraft had reported engine-related problems on three occasions, but there was no conclusive evidence connecting this with the runway.

BBC: Jet2 resumes flights from Belfast International Airport

The airport said one Jet2 aircraft has reported engine-related problems on three occasions, but there is no conclusive evidence connecting this with the runway.

BBC: A Jet2 plane

In a statement on 19 October Olaf said its investigation had "found no conclusive evidence of the direct participation of Commissioner Dalli in the operation for requesting money".

BBC: John Dalli row: EU's Barroso denies ousting colleague

While there is no conclusive evidence of chemical weapons at Khan Aasal, U.S. and other officials have not ruled out the possibility that harmful chemicals were emitted as a result of an attack in Syria.

WSJ: Syria Chemical Report Spurs Probes, Theories

Gareth Davies, Chief executive of the Cleft Lip and Palate Association, said past studies had indicated that taking folic acid may help prevent cleft lip and palate in so called "high risk" groups but until now there had been no conclusive evidence to back this up.

BBC: Folic acid 'cuts cleft palate risk'

Registered nurses and doctors administer the drips at Tenteki, but there's no conclusive medical evidence to back up the health claims.

CNN: Vitamin cafes: Japan's latest health injection

But there has been no conclusive scientific evidence to back such claims.

WSJ: High Tea Has a New Meaning