Home Minister Hishamuddin Hussein said the deportation to Saudi Arabia was legal and that Malaysia cannot be seen as a safe haven.
Hamza Kashgari, 23, was sent back to Saudi Arabia on Sunday.
Mr Kashgari’s controversial tweet last week sparked more than 30,000 responses and several death threats.
Insulting the prophet is considered blasphemous in Islam and can be punishable by death in Saudi Arabia.
He has since removed the tweet and apologised for his comments.
Amnesty International has said that Mr Kashgari is a “prisoner of conscience”.
“If he (Kashgari) faces execution back in Saudi Arabia, the Malaysian government will have blood on its hands,” said Phil Robertson, Asia deputy director of Human Rights Watch