HONOLULU - A letter from the Honolulu Police Department was posted on social media and caused commotion and confusion.

It stated medical marijuana use disqualifies people from owning guns.

HPD sent the letters out to at least 30 registered gun owners who also hold Medical Marijuana cards since January.

The letters to those 30 people say they have 30 days to surrender or transfer ownership of their firearms.

The confusion, some of which through social media, was that all gun owners who hold a medical marijuana card would have to turn in their weapons in as well.

That's not the case. HPD is currently reviewing its policy. 

There are nearly 20,000 registered medical marijuna patients in Hawaii.

Island News was told, the number of those who also have guns hasn't been tallied.

HPD says the only way it knows if someone has both a firearms permit and a medical marijuana card is if that person tries to get another gun, after they got their card. 

Their name would then be flagged in HPD's database and receive a letters that says they need to surrender all of their current weapons.

Aside from the 30 individuals who already received the letter, other gun owners who also use medical marijuana could fly under the HPD's radar if they remain status quo, as long as they don't go in for a new permit.

Still, gun advocates say this system isn't right.

"If it's medicine and it's not being given to you for a medically disqualifying characteristic in your personality, it shouldn't be illegal, they should not be able to take away your constitutional right because you're taking legal medicine," Harvey Gerwig with the Hawaii Rifle Association said.

Gerwig hopes HPD backs off of its policy because he believes it could end up with lawsuits.

HPD's current policy requires gun owners to get a doctor's clearance before getting their guns back.

Those owners would also have to give up their medical marijuana cards and wait for a full year before getting that clearance.