Rappers replicate American accents in Persian rap, indulge in obscene lyrical content (mostly unprintable American slang), and often use female voices as leads or background voices - all jarring symbols of western decadence in the eyes of Iranian authorities who blame such music for diverting its youth away from Islamic culture.

But despite the restrictions, Felakat and countless other rap musicians are demigods of Iran's 'underground music' scene - an expression that applies to any group which fails to obtain a recording licence from Iran's Culture Ministry, and distributes its albums illegally through the flourishing black market.

In a country where 70 per cent of the population is under 32 - due to a demographic boom dating back from the 1980s - society is strongly influenced by the young. Rap for the young finds much appeal, much to the chagrin of the regime, invading homes and Tehran's equally forbidden party circuit.

Felakat is aware of his appeal. He coyly admits his female fan following has 'become fanatical' since the release of Nazgol, his hit track with love and fidelity themes, in March last year.

'I've had to change my mobile phone number twice,' he grins, a cigarette dangling between his lips.

With the introduction of satellite television in Iran in the early 1990s - also illegal in Iran - and the popularity of American artists like 2pac and Eminem, hip hop found an explosive following among Iranian youth who recreated the genre in Persian rap. Rap composers and producers soon followed.

In the last few years, a vast spectrum of rap musicians has emerged in Iran. Zedbazi, for instance, introduced Gangster Rap with their song Mehmooni (or In the Club). The most famous rapper, Soroush Lashkari, who styles himself with the screen name Hich Kas (Nobody) is considered the father of Persian rap.

And astonishingly, in a country where singing is banned for women, female rappers also dot the landscape. The first of the female hip hop and rap artists was Salome, who lives in Tehran and focuses on social issues like the miseries of the war in Iraq, and prostitution. Mana, another female rapper from Tehran, is famous for Rebellion, a song on poverty and runaway girls in Iran.

Underground bands from Iran now perform concerts in the United States, Britain, Canada and The Netherlands, with the albums they produce more popular than those of many professional singers.

Given the restrictions, CDs of rappers are sold illegally or pass from hand to hand and are copied with little regard for copyright.

Rappers have also invaded YouTube quite comprehensively.

But despite the fame, there's little money in the business because of tight regulations.

Most CD shop owners refuse to sell underground music, fearing raids by authorities. If caught, they face imprisonment and hefty penalties. Concerts in private gatherings occasionally get cancelled due to threats from ad-hoc neighbourhood Islamic vigilantes, who are staunchly opposed to music other than religious music.

'This is why many of us try to migrate abroad,' says Felakat, who is also weighing his options.

In March last year, the government of President Mahmoud Ahmadinejad filtered a number of underground music websites. In late April last year, when the authorities launched a campaign to enforce the Islamic dress code and orchestrated a comprehensive crackdown on fashion, they also took steps to curb underground music. A number of underground musicians were jailed, their recording studios raided and shut down.

Most of the singers who were rounded up undertook not to produce any more underground music, and some were freed on bail.

Felakat was one of those arrested and released later on bail after his father deposited his house as security in court.

Mohammad Dashtgoli, an official with the Culture Ministry which is responsible for vetting music 'in accordance with Islam' recently said he wanted to 'find a solution' to counter the internet distribution of Persian rap.

'There is nothing wrong with this type of music in itself,' he told the Iranian media. 'But due to the use of obscene words, rap has been categorised as illegal.'

However, some rappers say that mullahs, who wear both the turbans of religion and the hats of government in Iran, are stifling their creative freedoms and creating an oppressive atmosphere of Islamic purity and, ironically, that's making Iranian youth less religious, not more.

Rap is emerging as a form of protest music, as rappers continue to audaciously defy authorities, despite the crackdowns, thriving on their popularity and appeal among the young.

One group - who cannot be named for their own safety - regularly perform at private gatherings. They admitted in a private interview that they recently performed for a gathering of the Jewish community in Tehran, despite the staunch anti-Semitic stance of the Iranian regime.

They were forced to cancel the same programme three months ago after a tip-off about an imminent raid.

'Any music - even rap - is not un-Islamic,' says Mahmoud, 25, a composer of rap music, whose rap screen name is '.S'.

Mahmoud has composed about 100 songs, 80 of which are rap. Only two of them have clearance from the Culture Ministry as they deal with religious themes.

'There's hardly any motivation to seek clearance,' he says. 'If we adhere to their red lines, rap will be ruined. So most of us just throw up our hands and say, 'Oh, forget it!''

Although defying authorities, most rappers steer clear of political themes - a no-go zone in Iranian society - lest that invite even more vicious crackdowns.

Mahmoud is hopeful that rap music will be legal one day in Iran. 'The youth are the majority, and they cannot ignore their aspirations,' he says. 'If rap becomes legal, my albums will sell like hot cakes.'