The SSPCA has described the law banning hunting with dogs as full of loopholes and difficult to implement.
Dogs may now only be used to drive a fox towards waiting guns
The claim followed a decision on Tuesday to drop a case against Trevor Adams from the Duke of Buccleuch foxhounds.
Mr Adams had earlier been acquitted in another case under the protection of wild mammals bill.
Mike Flynn from the SSPCA said although he supported the law, it was proving difficult to prosecute.
Mr Adams was charged after public complaints about an incident on farmland near Kelso on 10 October last year.
Concern was raised about the pursuit of a fox which was subsequently killed.
Mr Adams told BBC Radio Scotland that he and fellow hunt members had not used loopholes in the law.
"We're using clearly written exceptions within the law to flush foxes to guns," he said.
"I think there's probably been a mistake on the part of complainants.
"They hear hounds running in the countryside and see horses and probably think we're breaking the law.
"What we're doing now is totally different to what we were doing before the 2002 ban on hunting."
Mr Adams denied that he and hunt members had used legal loopholes
Under the new law dogs may only be used to drive a fox towards waiting guns.
It is legal to shoot the animals but not to allow them to be hunted or killed by hounds.
Mr Flynn said: "When the law was being debated in parliament it was classed as a class issue.
"In a reverse way that's true because people like Mr Adams, who go out on an organised hunt with plenty of witnesses, will more than likely get away with it.
"Whereas if a couple of young neds go out with their dogs and are seen, they will end up in court and be found guilty under the same Act.
"It's a bizarre situation - the law is full of loopholes."