In a statement the Estonian Ministry of Interior said a prohibition on his entry to the country had been in place since December 12 - three days before his arrival on Monday but that he was either unaware of the fact or had ignored it.
He was able to get into the country because he came on a flight from fellow Schengen Zone state the Netherlands.
"Chiesa has visited Estonia in the past and has expressed his hostility towards Estonia on numerous occasions," the Interior Ministry said in a statement.
"For example, he has protected and justified the actions of Soviet Union activist Arnold Meri, who has confessed his participation in the deportations organized in Estonia in 1949. The tragic effect of the deportations to the Estonian society cannot be underestimated – tens of thousands of Estonian people lost their lives and homes and it is comparable to other crimes against humanity, such as the holocaust," the statement said.
Chiesa belongs to the organization GONGO Mir Bez Nazisma (MBN), which is known to be an instrument of Russia’s influence activities,"
"The actions and opinions expressed by Giulietto Chiesa give reason to believe that he is supporting the influential activities of Russia. The application of his prohibition on entry was not a means to restrict freedom of speech but to protect the Estonian public order and social security," it said.
On Monday Chiesa was detained in Tallinn and taken to the police department to explain himself and was ordered to leave the country. He returned to his hotel and left on a train bound for Moscow on Tuesday morning.
Estonia's ERR News reports that the Italian government in Rome has summoned the Estonian ambassador to explain why Chiesa was booted out.
Chiesa's moustachioed face was also a familiar face in Latvia in 2009 when he stood as an MEP candidate with the pro-Moscow For Human Rights In A United Latvia (PCTVL) party which has today morphed into the Latvia's Russian Union party while keeping most of its faces the same - the best known of which being Kremlin favorite Tatjana Zdanoka MEP.
He wrote a book about his failed effort to win a seat titled The Latvian Candidate.
As well as holding senior positions within the Italian Communist Party he had previously served as an independent Italian MEP.