Los Angeles  - Legalizing marijuana could contribute 1.4 billion dollars a year to state coffers, according to a study by California tax officials released Wednesday.

The state Board of Equalization's estimate of the tax yield on pot sales comes as the state is in dire financial crisis. The board launched the study in response to a proposal by San Francisco Democratic Assemblyman Tom Ammiano to regulate cannabis much like alcohol.

The study estimated that some 500 tons of cannabis would be taxed each year and forecast that legalization would increase consumption by 30 per cent.

While law-enforcement groups staunchly oppose the measure, proponents argue that a tax would generate much-needed revenue for the state, restrict access by those under 21, end environmental damage caused to public lands by illicit crops and redirect police efforts to "more serious" crimes. (dpa)