3 stars

The Hollywood buddy movie as we know it comes in various generic guises and is often framed as comedy with two male leads. In buddy movies it usually takes two, but on this occasion, it has taken three.

This French cop action film with its three male leads is a kind of policier. Yet the film, screening on Netflix, has much in common with the knockabout buddy movie in which mismatched partners lean on each other to get things done, and have a good time while they're at it.

It's about a trio of plainclothes policemen who work together in an anti-crime unit, known in France as the BAC. The film's alternative title is BAC Nord, the name of the anti-crime squad that covers the northern Marseille, the great port city in southern France where many different immigrant communities live side by side, and worlds apart.

Director Cedric Jiminez, who grew up in Marseille, wrote the screenplay with Audrey Diwan. It is loosely based on true-life events.

The buddies comprise three distinct types. The team leader, Greg Cerva (Gilles Lellouche) is older, self-contained and has no family. He has been a "popo" or cop for 20 years. His two sidekicks are Antoine (Francois Civil), who is athletic, bronzed and wears his hair in a man bun, and baby-faced Yass (Karim Leklou), who looks gentle but has a nasty habit of slapping people around to get compliance.

Each has a different style, just like earlier cop buddies such as Danny Glover and Mel Gibson's characters in the Lethal Weapon films and Ben Stiller and Owen Wilson'd characters in the film adaptation of Starsky & Hutch.

The flics in The Stronghold riff off each other too, ehether they're grooving to rap music turned up loud as they weave through the traffic, or sharing cartons of contraband cigarettes, or tucking into merguez sausages and tabbouleh at a barbecue. Getting to know them reveals they are not so very different from the communities they police.

Over lunch at Yass's place, when there is a bit of banter around the table, Nora speaks her mind. Yass is a hard man on the job but he is sweetly in love with his gorgeous, pregnant wife (Adele Exarchopoulos), who works as a police despatcher. When Nora's waters break, the siren is slapped on the roof and the boys take her to hospital, but not before she has delivered some very good lines.

Greg, Antoine and Yass have each other's backs. When things don't go to plan, like losing a suspect they were chasing on a clapped-out motorbike, they look for alternatives. To make up their quota, they make a sortie into the high-rise ghetto to arrest a small-time dealer instead, and at the markets stop a hapless pair doing an illegal trade in baby turtles.

Chasing suspects that get away, or being barred from the ghetto by its self-styled security, makes the flics feel pretty ineffective, until the day the boss gives the signal to take down the entire narcotics network operating in the ghetto area. Antoine works on his pretty informant Amel (Kenza Fortas) and acquires the intelligence the BAC Nord need. A large shipment of drugs is arriving and a police raid will catch the vast dealer network red-handed.

A major corruption scandal in Marseille in 2012 saw a gang of policemen arrested for organised drug theft and extortion. The filmmakers based their screenplay loosely on the stories of several of the officers who were unwittingly caught up in the criminal activities, or unable to operate outside them.

As the performances here aren't that persuasive, the policing is most convincing in the chase scenes, so long as the music track that has landed abruptly doesn't distract from the action too much. Many of the extended chase sequences captured with a hand-held camera are immediate and exciting, while the climactic scenes when the flics are on foot in the ghetto have a convincing urgency.

The Stronghold is an entertaining but uneven mix of knockabout fun and seriously compromised policing. Gilles Lellouche is in character and Adele Exarchopoulos makes a big impression in her small part, but overall, it just doesn't all hold together well. Not as well as those Marseillais tower blocks, anyway.