A move that would bar cops from keeping property and cash seized in drug cases when there is no criminal conviction is the flash point of a debate between law enforcement and civil liberties advocates that is ­heading to the Legislature as soon as next week.

Backers say the state’s civil forfeiture laws are long overdue for a little due process. The laws have become a growing source of cash for law enforcement agencies and were famously abused by the now-defunct Metro Gang Strike Force, which paid out $840,000 in settlements to ­victims who had their property illegally seized.

Under current law, police or sheriffs can keep property, vehicles and cash seized in drug cases or drive-by shootings — regardless of the outcome of the criminal case. If a suspect is found not guilty, they can still lose their property in civil court unless they can prove it was not involved in a crime. The bill would require prosecutors to return the property if there is no criminal conviction associated with the seizure. A companion bill would allow spouses and other innocent owners to raise claims when their property is forfeited due to someone else’s criminal activity.

Lee McGrath, executive director of the Institute for Justice’s ­Minnesota chapter, said that between 2003 and 2010, law enforcement agencies supplemented their budgets with $30 million gained through forfeitures. That, McGrath said, represents a 75 percent increase despite a small drop in the crime rate. The bill has received broad bipartisan support.

“It’s a great example of how legislators are increasingly concerned about policing and prosecuting for profits,” he said.

But the Minnesota County ­Attorneys Association says the bill goes too far. The group maintains that reforms have already eliminated the potential for abuse, and that the bill as written could wind up keeping more guns on the street.

MCAA Executive Director John Kingrey said his organization supports fairness and transparency in the state’s forfeiture laws, but that the bill is ripe for abuse.

“Drug dealers are smart people,” Kingrey said. “One of the challenges we have is we walk in the door with cocaine and $10,000 sitting on the table, with five guys saying ‘That’s not mine.’ Four of them get convicted, and the fifth guy says ‘That money was mine, I wasn’t convicted, give me the dough.’ ”

It’s not just money, Kingrey said. Acquittals could also put guns back on the street.

“When you see drugs, you see guns and this would make it more difficult to seize and forfeit guns,” Kingrey said.

The American Civil Liberties Union has jumped into the fray, saying Minnesota’s civil forfeiture laws are too broad.

Advocates and prosecutors disagree about what is required in criminal court before property can be permanently forfeited. There is some question over whether a “stay of adjudication,” when a conviction is deferred and later erased, should count as a conviction. Or when property is seized in connection with a felony, but the suspect pleads guilty to a lesser charge where seizure wouldn’t be warranted.

“Conviction is a very jazzy term, but it’s more nuanced,” Kingrey said.

McGrath called the disagreements “a guise for law enforcement’s refusal to negotiate about reforming the forfeiture laws.”

Rep. Susan Allen, DFL-Minneapolis, the bill’s sponsor, said her proposal is “modest judicial reform” that could have a big impact. Allen said the average forfeiture now is about $1,100. She contends her bill has support beyond just those who have had their property seized.

“When you talk to law enforcement, they don’t like it either,” she said. “They’re about integrity, and it doesn’t sit right with people.”