Greece's migration minister on Sunday dismissed fresh claims that migrants are being illegally pushed out of the country as "fake news" promoted by Turkey.
He was reacting to reports by rights groups that thousands of people had been forced back into Turkey in recent months in violation of their right to asylum.
"These are part of a broader fake news strategy promoted by Turkey, through certain non-government organisations and smuggler networks," Migration Minister Notis Mitarachi told To Vima weekly.
"Investigations until now by (EU border agency) Frontex and the (Greek) coastguard have not confirmed any of the claims," he said.
Greece has consistently denied claims by migrant support groups that it is illegally returning migrants to Turkey in violation of international law, including two reports this past month.
Berlin-based rights group Mare Liberum said Friday it had documented 321 incidents from March to December 2020 involving more than 9,000 people.
They had been "violently pushed back to Turkey and thus deprived of their right to asylum", said the group.
Another group, Legal Centre Lesvos, said earlier in February that it had been in contact with more than 50 survivors of 17 collective expulsions.
Mitarachi on Sunday insisted that Greece's borders were being guarded "under the framework of international law and European values".
Since its election in 2019, Greece's conservative government has strongly prioritised border security and adopted a tough migration policy.
Mare Liberum's report on Friday said that in addition to the Greek coastguard, Frontex and ships under NATO command were also involved in "systematic and illegal expulsions".
Frontex is currently under investigation by OLAF, the EU's independent corruption watchdog, over the issue.