Prisons have become more dangerous in South Australia due to a 73 per cent increase in the amount of bikies jailed over the past five years, State Police Minister Peter Malinauskas has admitted.

Mr Malinauskas said the increased number of incarcerated bikies has meant additional resources were required within the prisons and it had created "unique challenges" for the system.

This includes complications surrounding contraband, visitation rights, and which bikies can interact with others.

"There are occasional acts of violence that occur within the prison system," Mr Malinauskas said.

"These need to be prevented as best as they possibly can. The good news is, whenever a bikie is behind bars, it means they're not in the community.

"It's far better to have these organised crime elements in jail, rather than in the community committing crimes."

But Mr Malinauskas said the 73 per cent increase of jailed bikies was proof that amended laws declaring 10 gangs as criminal organisations in 2015 were working.

It enabled police to target Outlaw Motorcycle Gang members in special operations, led to the closure of some bikie headquarters, and banned members from meeting or wearing club colours in public.

"That's made a substantial contribution to less crimes on our streets, but also to less drugs in our community as well," Mr Malinauskas said.

"We've seen a reduction coinciding over the last two years with the number of people who are members of Outlaw Motorcycle Gangs.

"That number is down from 308 to 239 over the past two years.

"[But] they don't tend to stop committing crimes at the prison gate, which is why we have to work hard to make sure that they are incarcerated at the appropriate facility."