He is one of South America's most powerful televangelists, a billionaire preacher and media mogul who presides over one of the world's fastest-growing and most controversial Pentecostal churches.

But despite controlling one of Brazil's largest communications empires, Bishop Edir Macedo, the head of the Universal Church of the Kingdom of God, is urging his followers to embark on a complete media fast. Twitter and Facebook-obsessed Christians have been told to log-off and get closer to God.

"It will be a fast from each and every kind of secular information: TV, internet, newspapers, magazines, radios … from everything that is not Godly," Macedo wrote.

Many suspect the move, however, is a tactic to divert followers' attention from bad press.

The Christian news website Gospel+ noted that Macedo had called for "media fasts" twice in the past. On both occasions, the fasts coincided with negative stories about the Universal Church that were widely disseminated in the Brazilian media.

Earlier this month the Universal Church came under attack after claims that a nine-year-old boy had been coerced into selling his toys during one televised service. As his mother underwent a violent exorcism on stage, the boy told the preacher he hoped selling his toys and donating the proceeds to the church would stop his parents fighting at home.

Promoting the media fast his popular blog, the Blog do Macedo, the preacher claimed: "The spirit of the Lord will descend upon all sincere participants."

"In the first 21 days of August we will carry out a veritable spiritual clean-up," he added, calling on believers to "abstain from all forms of media and entertainment ... from all the trash of this world."

His numerous critics believe that while the fast will prevent churchgoers from following the latest developments on spicy telenovelas shown by Brazil's Globo media giant, they will be allowed to tune in to programmes on Macedo's rival Record network, as well as religious services.

Followers will also have access to Macedo's websites, radio stations, record label and the church's weekly newspaper, the Folha Universal.

One blogger suggested Macedo himself was unlikely to adhere to the media blackout since people who worked for or depended on the media were exempt.

Macedo's church was founded in 1977 in Rio de Janeiro and has since grown at a breakneck speed. Today it claims to have some 8 million followers worldwide, including "temples" in Africa, Asia, Europe and the US. Brazilian authorities have claimed that bishop Macedo is worth at least $2bn.

Earlier this month, the church opened its latest temple in the UK, inside a former cinema in Leicester. "This is no longer a cinema, but a church, a spiritual intensive care unit," Bishop Celso Júnior, one of the Church's UK leaders, reportedly said at the launch. The "gates of hell would never close on the city of Leicester", he added, according to the Arca Universal website, one of Macedo's numerous media outlets.

The church's hostile stance towards gay and lesbian people mean the church has become one of Brazil's most controversial.