Mother Teresa will inch a step closer to sainthood when the pope approves on Friday a miracle attributed to her.

A statement from the Vatican, released in Kolkata, said: "The Pope will on December 20 approve the decree on Mother Teresa's heroic virtue and the miracle attributed to her intercession."

With Pope John Paul II officially certifying the miracle, the process of beatification will be complete.

Teresa can finally be canonised after the Roman Catholic Church accepts a second miracle attributed to her.

The statement said the date and place of the Albania-born nun's beatification will be announced after the pope gives his approval.

The miracle to be approved by the pope relates to a tribal woman named Monica Besra, who reportedly recovered from a stomach tumour after wearing a medallion with Mother Teresa's photograph.

This supposed miracle was at the centre of a controversy in October when doctors who had treated Besra said she had been cured by medication, not some miracle. 

The Church claims that Besra's case was certified by doctors as "beyond the comprehension of medical science" and says it has sent "clinching physical evidence" in support.

The Church has already made an unprecedented concession in Mother Teresa's case, allowing the process of canonisation to start only about a year after her death. Usually, a candidate for sainthood has to go through a mandatory five-year waiting period after death.

Mother Teresa, whose real name was Agnes Gonxha Bojaxhiu, came to Calcutta in 1929 and began a life dedicated to the poorest of the poor.

She is the 14th person to be considered for sainthood from India. She founded Missionaries of Charity, in 1949. Mother Teresa won the Nobel Peace Prize in 1979. She died on September 5, 1997.