An independent committee concluded on Wednesday that the Intelligence and Security Services Act (Wiv) does not meet some important requirements.
The law must therefore be amended, reports the national government.
The Wiv, introduced in May 2018, popularly known as the dragging act, was the subject of considerable political and social debate at the time.
It even led to a referendum.
The committee, led by Renée Jones-Bos, has now concluded that the law is not satisfactory in all areas and comes with a number of recommendations to reform the law.
The changes must already be included in the forthcoming cabinet formation, the report says.
The Wiv provides the secret services General Intelligence and Security Service (AIVD) and Military Intelligence and Security Service (MIVD) with more and more extensive investigation possibilities.
A major point of contention was the possibility of intercepting large amounts of data (bulk data) in investigations into potentially suspicious persons and / or organizations - also from people who are not and never will be part of the investigation.
The committee believes that the collection and use of this bulk data should be handled more carefully.
"Both acquisition and processing should be better regulated in law," said the committee.
Recently, the European Court of Justice said that the non-targeted collection of telephone and internet data is contrary to European privacy rules.
The Committee also believes that more attention should be paid to the exchange of data with foreign services.
"It should be included in the law that no data will be shared where there is a real risk that use by the receiving service will be a flagrant violation of international law, and in particular human rights and international humanitarian law."
According to the committee, there should also be a role for the Council of State.
The law now has a number of vagueness, such as intercepting data "as precisely as possible".
This can cause confusion.
The judge could give substance to this, according to the committee.