VANCOUVER - A report from the Fraser Institute says British Columbia's carbon tax is no longer revenue neutral.

The study, co-authored by Charles Lammam, director of fiscal studies at the right-wing research institute, says the B.C. government no longer cuts other taxes to roughly equal new revenues from the carbon tax.

Without that offset, the study finds the province is collecting millions of dollars of additional funds from taxpayers, which Lammam says violates the government's commitment that the tax would remain revenue neutral.

The study says the tax was revenue neutral up until 2013, when the government stopped providing new cuts to offset the additional carbon tax revenue that it was collecting.

Once the pre-existing tax reductions are excluded, the Fraser Institute says B.C. taxpayers paid $226 million in increased taxes in 2013-2014 and $151 million in increased taxes in 2014-2015.

No one from the B.C. government was immediately available to comment on the study's findings.