The Geo Barents ship was impounded late Thursday for 20 days and will be fined between 2,000 euros ($2,100) and 10,000 euros ($10,590), MSF spokesman Maurizio Debanne said.
The charity said it had been accused of failing to share information, including voyage data recorder (VDR) information on the position and movement of the ship, something it says it has never before been asked to share.
Debanne linked the detention of the ship, which is in Sicily, to a new decree introduced by Prime Minister Giorgia Meloni's government.
Meloni, the leader of the far-right Brothers of Italy party, took office in October after promising to curb the number of migrants landing in Italy.
The new decree, which was converted into full law by parliament on Thursday, obliges charity ships to only perform one rescue at a time.
Critics say it increases the risk of deaths in the Central Mediterranean, which is the most perilous crossing in the world.
"It's unacceptable to be punished for saving lives," MSF said, adding that it was considering a possible legal challenge.
The seizure and fine follow a complaint by the port authority in Ancona, where Geo Barents brought 48 rescued migrants on February 17.
Italy's geographical position makes it a prime destination for asylum seekers crossing from North Africa to Europe, and Rome has long complained about the number of arrivals.
Over 14,000 migrants have landed in Italy since the start of the year, according to the interior ministry, up from just over 5,300 in the same period last year and 4,300 in 2021.
Charities only rescue a small percentage of those brought ashore, with most saved by coastguard or navy vessels.
But the government accuses charity ships of acting as a pull factor and encouraging people traffickers.
Italy Docks MSF Migrant Rescue Ship
Italian authorities have detained a migrant rescue vessel run by Doctors Without Borders (MSF) for allegedly breaking new government rules on life-saving missions in the Mediterranean, the charity said Friday.
ROME —
