Indian authorities have increased security for a high-ranking Catholic Church official, who said he Maoist group threatened him for spreading religion in Jharakhand state in the east of the country.

Cardinal Telesphore Toppo said the group demanded 50 million rupees (about $780,000) from the church, which the People's Liberation Front of India claimed to be money made spreading religion.

The letter was sent to the cardinal through registered mail and signed by a man claiming to be a member of PLFI, a breakaway faction of the Communist Party of India, nyooz.com reported.

"You have made moolah [money] by spreading religion, which is why you should give a cut to the organization," stated the letter, signed by Raj Kujur, a self-styled PLFI commander operating in the area.

"The police do not have the capacity to arrest our men," the letter continued. "If you do not pay, you will be killed."

The extortion demand gave the cardinal 15 days to produce the money.

Jaya Roy, the city police superintendent, said he put officers on heightened alert after learning about the threat.

"The cardinal is an important leader of the Christian community. We have provided adequate security at his house. He will also be given security cover when he moves," Roy said.

Police are checking on the source of the letter, sent from Kuchhu village, on the state capital's outskirts.

In an interview with ucanews.com, Toppo expressed dismay at the threat, saying that peace has prevailed in the community where the church and Maoists worked together.

He noted that the rebels have been "appreciative" of missionaries' work in India's remote villages.

"Why on earth they have taken this step, we are wondering," the cardinal said.

Toppo tried to verify whether the letter came from the PLFI, saying he had made contact with a member.

The person, unidentified for security reasons, denied the group sent the letter, said Toppo, who read the note after arriving from Germany.

"Even if the threat is real, we won't pay, primarily because we don't have money," he said. "If we don't have [money], how will we pay?"

Observers say PLFI members are under police protection because authorities use them to counter threats from Maoist rebels. But the group has gained more power since it has grown.