God will use the case of the Christian governor in Jakarta accused of insulting the Qur'an to witness to other Christians, his sister has said.

Fifi Leity Indra, sister of Governor Basuki Tjahaja Purnama – who is known as Ahok – said according to CBN News: "He [Ahok] understands that he may receive persecution because of what he believes. He also believes that God is going to use this as a showcase to make people have more strong belief that in everything God is in control."

She insisted that the accusations Ahok had blasphemed were untrue.

The governor allegedly insulted the Qur'an while he was campaigning ahead of elections in February for the governorship of Jakarta, which is the capital of the world's largest Muslim-majority nation.

Ahok is ethnic Chinese and the first Christian in nearly 50 years to govern Jakarta.

In a speech to fishermen in September, he reportedly cited a verse from the Qur'an that warns Muslims against taking Christians and Jews as allies. He is said to have added that due to Indonesia's transition to democracy in 1999, it was perfectly acceptable for Muslim voters to choose a Christian in the election for governor in February.

Ahok has denied the charges, saying that his comments were aimed at politicians "incorrectly" using the Koranic verse against him.

Blasphemy convictions in Indonesia almost always result in conviction, and the law has been criticised by Amnesty International for hurting freedom of expression and for targeting religious minorities.

Indonesia technically guarantees freedom of religion in its constitution but in reality only six religions are recognised and tough blasphemy laws control debate and target minorities.

Christians represent less than 10 per cent of the 250 million population.