Prosecutors have insisted there is no gap in the law when it comes to the use of video evidence in wildlife crime cases.
MSPs on Holyrood's Environment Committee questioned whether a review of the legislation was required after several cases of alleged raptor persecution were dropped.
Last year the RSPB criticised the Crown Office after video footage gathered by the charity was deemed inadmissible.
Tory MSP Finlay Carson raised the issue of "public frustration" in such cases.
He said: "When was the legislation last looked at and with advances in technology is it something that we really need to seriously take a stand on and look at what technology is available and try to change the legislation to be fit for purpose?"
Sara Shaw, head of the Crown Office wildlife and environmental crime unit, said the proportion of cases not taken forward because of the inadmissibility of video evidence was "relatively small".
She added: "I think it's difficult to say what legislative change would be meaningful in the abstract without a specific goal in mind.
"It is possible to use video evidence as evidence in a prosecution, the question is what are the full facts and circumstances surrounding the obtaining of that evidence that can impact on the admissibility.
"I think it's fair to say from a Crown perspective we've not identified a huge gap in the law.
"Obviously it would be for the Scottish Government to consider whether a further development of legislation is required to address any concerns surrounding the use of covertly obtained video evidence in the context of wildlife crime."
Laura Buchan, head of the Crown Office health and safety division, acknowledged the admissibility case followed by prosecutors dated to 1950.
She said: "To some that would sound archaic but actually what the law does and what investigators do is they evolve in terms of whats facing them.
"I'm not concerned about the kind of lack of legislation if there's a consideration around that, I think that our law develops as that progresses."
Sean Scott, Police Scotland detective chief superintendent, said directed surveillance had implications for human rights and was an issue for wider public debate.
Sergeant Andrew Marvin, Scottish wildlife crime coordinator, added: "It's the impact this would have on wider legislation away from wildlife crime.
"That's what you've always got to remember in the background here. If we were to allow that in wildlife crime situations, what's the next step?"