A key article of a new security law in France that could result in prosecutions of people who publish footage of police officers in action has been rejected, the county's top constitutional authority said on Thursday.

The Constitutional Council said legislators who approved the controversial law failed to clearly establish what would constitute a violation of the law in such situations.

The legislation, Article 52, is part of a security law drafted by President Emmanuel Macron's ruling party and adopted by parliament in mid-April.

It states anyone causing police officers or other members of security forces to be identifiable during an operation could face up to five years in prison and a fine of 75,000 euros ($90,000).

However, the Council said the law did not specify whether this related only to live operations or also to past ones, and what exactly constituted a police "operation".

It also said it was unclear whether any "malevolent" intent to identify officers was already grounds for prosecution, or whether only the actual publishing of images was punishable.

"The Constitutional Council concluded therefore that the legislative body did not sufficiently define the elements that constitute the offence in question", the Council, which also took issue with other articles of the law, said in its ruling.

Following the ruling, French Interior Minister Gerald Darmanin said he would seek "to improve the provisions that were the subject of reservations by the Constitutional Council".

Opponents of the law argue that the security law will make it more difficult for journalists and citizens to document cases of police brutality.

The government has argued that the law is needed because police officers have become targets of attacks and calls for violence against them on social media.

Hundreds of protesters demonstrated for many weekends at the end of last year against the law, with some of the demonstrations resulting in rioting.

The demonstrations intensified after the publication of video footage showing a Black man being beaten up by three police officers inside his own music studio in November.

(With input from agencies)