The mass forced return of refugees from Turkey to Syria exposes the flaws in the EU-Turkey deal, according to Amnesty International.
The new research suggests that Turkish authorities have been sending groups of asylum seekers to Syria on a daily basis since mid-January this year.
The human rights organisation said that Turkey is not a safe country for refugees.
Meanwhile, EU officials have expressed the hope that returns could start from next Monday, April 4.
Colm O'Gorman of Amnesty International Ireland said the EU needed to stop putting desperate people at risk, suggesting "it needs to respect the human rights of those who need protection in Europe... and stop placing desperate people at even greater risk":
He said he wanted to convey these messages to EU leaders:
"Honour your obligations under international human rights law, and under European law.
"Provide safe and legal routes for people to apply for protection in Europe, and if they're legally entitled to protection, give them that protection.
"Shut down the routes for smugglers by opening up safe and legal routes in line with the requirements of international law, and respect the rights of refugees."