Drug use remains a problem in South Australian prisons, the state opposition says.
The opposition's correctional services spokesman Dan van Holst Pellekaan has released figures which show there were 839 positive drug tests in SA's jails in 2012/13.
He says that's the highest level in recent years with 831 positive tests in 2009/10, 798 in 2010/11 and 824 in 2011/12.
Cannabis is the most common drug detected with 430 positive tests last financial year.
"We've known for a long time that illegal drugs in prisons are a problem but what is of grave concern is that the Labor government is making no progress tackling this problem," Mr van Holst Pellekaan said in a statement on Monday.
"It is completely unacceptable that there are over 839 known instances of drug taking out of a total prisoner population of 2252."
Comment is being sought from the state government.
A Correctional Services Department spokesman says the rise in positive drug tests could be attributed to greater intelligence-based targeting of suspected illicit drug users, a rise in the prison population and more testing of prisoners moving to lower-security regimes.
He said while the average prison population in 2012/13 was less than 2300, 4600 passed through the prison system with most only jailed for about three months.
"Drugs in prisons is an issue faced by every jurisdiction both nationally and internationally," he said.
"No jurisdiction can boast a drug-free prison system."