People refusing to get Covid vaccines in France are coughing up hundreds of euros for fake health passes in an online black market that has flourished since the government required them to enter cafes, inter-city trains and other public places.

People have had to show proof they have either been vaccinated, tested negative for Covid or have recovered from the disease in order to enter a museum, cinema or sports venue since July.

It was expanded to restaurants, bars, hospitals and trains earlier this month as President Emmanuel Macron seeks to compel people to get vaccinated.

While surveys show most French support the measure, opponents have held protests for five straight weekends.

And a black market for fraudulent health passes has sprung up on Snapchat -- despite the risk of jail sentences.

Accounts on the social networking app that rarely last for more than a few days openly advertise their counterfeit documents.

Some ads say: "Your health pass by email in eight to 10 hours maximum", "Vaccination is optional thanks to our service" or "Say no to the vaccine and get a health pass without getting vaccinated".

A 28-year-old event planner told AFP he obtained his fake health pass for 350 euros ($410). The Covid-19 vaccine is free in France.

He said he isn't anti-vaccine, but that he doesn't feel that young people should be forced to get vaccinated when he believes they aren't particularly vulnerable.

"If Covid-19 still exists when I'm 50 or 60, then yes, I'll get vaccinated," he said, speaking on condition of anonymity.

He said getting regular tests to show that he isn't infected wasn't really an option as he risks a positive result which means he couldn't work.

"Security guards told me that even if I am the person organising the party, if I'm positive, I can't get into my own event," he said.

He said he wasn't worried about getting scammed as he has friends who had already bought fake health passes.

All one needs to do is type in "fake health pass" to find dozens of offers on Snapchat. They can also be found on Facebook, with some apparently paying to have their offers put into user feeds.

One has to provide all the basic information necessary to have real functioning health pass, including a French health system number.

Visitors present health passes (pass sanitaire) to a security guard at the entrance of a movie theatre in Montpellier
Visitors present health passes (pass sanitaire) to a security guard at the entrance of a movie theatre in Montpellier AFP / Pascal GUYOT

"I send all the information to my doctor contact who registers it in" the French national health system database and the phone app for the health pass, said one counterfeiter.

As a health worker -- some complicit, others hacked -- enters the information into the computer system the person is considered by authorities to have been fully vaccinated and the health pass itself is real, not fake.

French health passes contain a QR code that is scanned by security guards at entrances to check against the national database, so counterfeiters prefer using doctors to fraudulently create real passes that function.

One doctor in southwestern France filed a complaint after discovering that his profile in the health insurance website had been used to make 55 fake passes.

Certain counterfeiters allow payment after verification the pass works in order to reassure potential clients.

Others don't need to as they have already earned reputations selling fake Covid test results.

Prices range from between 140 and 350 euros.

Payment is most often made via the French mobile payments app Lydia, or by clients buying prepaid payment cards or vouchers like Paysafecard and transferring the codes to the counterfeiter, allowing them to buy goods from websites.

"I use Paysafecard because unlike PayPal, its untraceable," said one counterfeiter.

The national health system says it has received a growing number of queries from police investigating fraudsters. It said it has made 30 criminal complaints and tips to police about suspicious behaviour.

The counterfeiters face prison terms of up to five years and fines of up to 150,000 euros. Those who use fake health passes could spend three years behind bars.

Several people have been charged so far for health pass fraud.

Scams selling completely fake QR codes also abound, but the authorities are focusing on those creating false vaccination records in the health system.

One woman has received a one-year prison term -- which was converted to home detention due to Covid -- for creating some 200 QR codes for sale.

She worked at a vaccine centre.