Tasmania Police say they want the state's anti-abortion protest laws tightened up if they are going to stop future campaigners.

Tasmania's Reproductive Health Act was passed last year and is designed to stop protest within 150 metres of clinics.

In September police prosecutors dropped the case against Queenslander John Graham Preston, who had been charged over protesting outside two Hobart termination clinics.

At the time they said that, after reviewing the Act, they did not feel they had a case.

Police Commissioner Darren Hine said that decision sparked an internal review.

"It's a learning opportunity. The review's highlighted a couple of issues and we just need to work with those," he said.

"We just need to have those discussions with that (Health) department and obviously with the minister to see what should and can be done."

It is understood police are not sure the legislation would be watertight if a protester mounted a vigorous defence.

Police are now working with the Health Department to identify the legislation's weaknesses.