A mysterious Facebook blogger purporting to be a disgruntled "Deep Throat" in President Robert Mugabe's party has become an unlikely election campaign star in Zimbabwe, attracting 275,000 online followers and the fury of the ZANU-PF establishment.

With a daily stream of social tittle-tattle, outrageous personal slurs and explosive - if true - political allegations, "Baba Jukwa" has created an unprecedented stir in the run-up to the July 31 poll.

His popularity reflects the rapid expansion of internet access and social media since the end in 2008 of a long economic meltdown, and the thirst of Zimbabwe's 13 million people for information beyond the ZANU-PF propaganda that dominates state media.

It also flirts with serious reprisals in a country where sensitive political matters are discussed only behind closed doors for fear of Mugabe's secret police, who can tap phones and intercept internet traffic in the name of national security.

Although senior figures in Mugabe's ZANU-PF party dismiss his posts as the ramblings of a disaffected lunatic, Baba Jukwa has ruffled enough feathers to merit denunciation in the Herald, Mugabe's state-controlled print mouthpiece.

"Baba Jukwa's thunder is waning as the stories become more and more ridiculous," the paper said in an editorial on Tuesday after Baba Jukwa alleged that police chief Augustine Chihuri had organised the secret printing of extra ballot papers.

"They are not based on any solid grassroots work and is mere gossip, which can never translate into electoral victory," it added, proclaiming ZANU-PF's primacy in the "social network battle" for votes.

In a socially conservative nation where public criticism of elders and political leaders remains taboo - Mugabe, aged 89 and in power for 33 years, qualifies easily on both counts - a mere mention of Baba Jukwa is enough to elicit a furious response.

"Baba Jukwa is a complete waste of time, completely idiotic," said Saviour Kasukuwere, a pugnacious ZANU-PF minister and prime target of Baba Jukwa's often very personal attacks.

"If you take Baba Jukwa seriously, you need your head examined," he told Reuters. "He's targeting me at a personal level, but I'm not shaken by that rubbish. We are serious people. It's just meant to discredit individuals."

Mugabe does not read the site, he added.

'My evil party'

Ever since the blog emerged in March this year, Zimbabweans of all political persuasions have sliced and diced Baba Jukwa's posts for clues to his identity.

The blogger describes himself as "Concerned father, fighting nepotism and directly linking community with their Leaders, Government, MPs and Ministers" and says more than 70% of his online supporters are in Zimbabwe.

His varied style, erratic use of grammar and prolific output - barely a day goes by without a torrent of invective against "my evil party" - suggest more than one author at work, but beyond that his identity or identities remain unclear.

Even the origins of his name are murky: Jukwa means nothing in any of Zimbabwe's major languages and appears to come from the word for 'podium' in Swahili, the lingua franca of Kenya and Tanzania.

Many of his allegations are impossible to verify and numerous calls by Reuters in Johannesburg to mobile telephone numbers posted on the site and said to belong to senior officials including Chihuri, the police chief, went unanswered.

The nature of the allegations, which include purported accounts from meetings of the ZANU-PF Politburo, the party's top 50 or so officials, suggests he is either a senior member of ZANU-PF or has access to senior members.

The Herald for its part denies that the Politburo has a mole. "Baba Jukwa claims that he is a member of Mugabe's inner circle," it said this month. "He is not."

Baba Jukwa's page was among the first outlets to report problems with early voting last week for 60,000 civil servants and police, long before they were officially confirmed. This suggests the site could play an important role in collating any irregularities or violence on polling day.

Whatever his identity or sources, Baba Jukwa's emergence has given ZANU-PF a glimpse of the future as technology erodes its dominance of information and political discourse inside Zimbabwe's borders since independence from Britain in 1980.

"It reflects a desperation and a hunger for information and understanding of what's going on," said International Crisis Group researcher Piers Pigou in Johannesburg. "And it's the first time they've ever had to deal with what you might say is their own medicine."