"It is true that repatriation of refugees from Burundi, the Democratic Republic of Congo [DRC] and Rwanda had been carried out by the government for several months. But that was being done on a voluntary basis," Joseph Mungai, the Home Affairs Minister, said on Wednesday.
The minister said the exercise was being carried out under agreements between Tanzania, the United Nations Refugee Agency (UNHCR) and the respective governments, so that only those who had expressed their willingness to return home were being assisted in that endeavour.
Mungai, however, said some of the refugees were not ready to return. He said officials from the governments of Tanzania, Rwanda and Burundi, accompanied by the UNHCR, had visited several camps to persuade the refugees to return home after the return of peace to their respective countries.
"I have personally visited several refugee camps to explain the situation," he said.
The minister, however, said there were hundreds of thousands of refugees outside the camps who had lived in Tanzania for a very long time.
"These people do not have refugee status and according to the law, they have to leave the country or obtain legal status either through naturalisation or by securing a resident permit," he said.
The minister admitted that illegal immigrants were sent home, but noted that legal procedures were adhered to during their transportation along with their property.
"The door is open for those with complaints about loss of property or unfair treatment," the minister stressed.
The New York-based agency Human Rights Watch (HRW) had earlier in the week written to President Jakaya Kikwete criticising his government's treatment of refugees and illegal immigrants.
"According to testimony received by Human Rights Watch researchers, some expelled persons were threatened, beaten and saw their property looted by Tanzanian officials, soldiers, and police officers or by militia groups acting with the apparent compliance of government officials.
"The expelled persons - including some who were recognised as refugees and others who were naturalised Tanzanian citizens - were driven from their homes without any semblance of legal procedure.
"It is urgent that you take action to prevent such ill-treatment in the coming months, especially since Tanzania has announced its intention to send tens of thousands more persons across the borders into Rwanda and Burundi," read the letter.
"All individuals claiming refugee status in Tanzania are protected under international law from ill-treatment and forced return to their countries of origin, pending determination of their claim," HRW added.
The organisation called for an investigation of the authorities responsible for violating the rights of the expelled persons, saying they should be held accountable.