A BBC Africa Eye investigation revealed in March that vast quantities of protected West African Rosewood was being trafficked through the country.
Most of it ends up in China, the Environmental Investigation Agency (EIA) found.
Gambian authorities have previously denied any involvement in the smuggling.
In June, the EIA published a report saying shipping companies were transporting contraband timber from The Gambia to China.
Three months previously, Africa Eye published an investigation into the million-dollar trade in trafficked rosewood.
Shipping company Compagnie Maritime d’Affrètement Compagnie Générale Maritime (CMA CGM), the world’s fourth largest, said that it had done its own investigations as a result of the evidence uncovered by the BBC and EIA.
“There was probably some protected rosewood inside their shipments from The Gambia to China,” said Guilhem Isaac Georges, Director of Sustainability for CMA CGM.
The company has therefore “decided to halt its timber exports from the country until further notice,” he told the BBC.
The shipping company also announced that it would create a global blacklist of shippers involved in the illegal trade of protected and endangered species.
The EIA said that it believed this was the first time a shipping line had banned transportation of an entire classification of goods.
What’s so special about rosewood?
Rosewood is a family of tropical tree species widely used for furniture in Asia and in particular China.
Also called Hongmu or “red wood” this rare and valuable wood is prized for its colour and durability.
It is used primarily for antique-style furniture.
How does the smuggling work?
Figures obtained by BBC Africa Eye showed that China has imported more than 300,000 tonnes of West African rosewood (Pterocarpus erinaceus) from The Gambia since President Adama Barrow came to power in 2017.
That is the equivalent of about half a million trees and worth more than $100m (£80m).
The Gambia is consistently among the five largest global exporters of rosewood, despite declaring its own stocks close to extinction almost a decade ago.
During a year-long investigation in both Senegal and The Gambia, multiple sources confirmed to the BBC that the rosewood being shipped out of The Gambia to China comes from the Casamance region of southern Senegal.
Along a 170km (105 miles)-long stretch of the border between the two countries, the BBC found at least 12 depots containing rosewood and other timber. They were all within Gambian territory.
The BBC investigations revealed that Senegal’s forests are being plundered at an alarming rate to support this trade.
In Senegal it is illegal to fell or export a rosewood tree and yet we saw evidence of this happening in broad daylight.
“It’s The Gambia that has to stop the export of rosewood. They make good speeches, good promises, they say: ‘We are going to stop’, but in reality it is not true,” said Haidar el Ali, a former Senegalese minister of environment, told the BBC.
The Gambia’s current government has also banned the export of pterocarpus erinaceus.
Under the country’s Forestry Act of 2018, importation from another country is only legal if it goes through an official port of entry. But all the depots we discovered have been active since Mr Barrow’s government has been in power.
The BBC also obtained footage showing truckloads of rosewood logs driving towards The Gambian capital Banjul earlier this year.
The government, however, denied the allegations contained in the BBC Africa Eye investigation.
Is there a legal trade in it?
In 2017 the West African rosewood tree was given international protection. It was listed under Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora – known as Cites. It is a multilateral treaty to protect the living environment.
The Gambian government, like Senegal, signed up to the international Cites convention. It permits a carefully regulated trade in rosewood so long as it is legal and sustainable.
Mr Isaac Georges said that in the current context in The Gambia, it was impossible to be certain that the country was abiding by the Cites regulations.
So CMA CGM decided “to go further than the local regulations to protect the environment”.
He added that: “The group acknowledged that ‘this highly sought-after wood is felled illegally in the region and then exported under various different guises.”
The timber sector in The Gambia is “plagued by opacity and corruption, it provides the perfect ecosystem for criminal networks to thrive,” Lisa Handy, Director of the Forest Campaigns at EIA, told the BBC.
CMA CGM said it hoped it was “demonstrating its leadership within the shipping industry in the protection of the environment.”
“It is a notable move and a very auspicious start… other shipping lines must also act,” Ms Handy said.