Saturday night in India's most cosmopolitan city and one question is on the lips – or fingertips – of many partygoers. "Anyone know where #Dhoble is going to strike tonight?" tweets one hedonist, referring to the Mumbai police chief who has become the first Indian cop to trend on Twitter.

To his fans, assistant police commissioner Vasant Dhoble is a modern-day hero who is doing his damnedest to save Mumbai from degeneracy. Armed with a hockey stick and a stiff moral code, he claims to work from 9.30am to 6am, carrying out up to four raids every day in his mission to clean up the city's bars and clubs. To his detractors, the 54-year-old police officer is Inspector Killjoy, an overzealous party-pooper armed with a raft of archaic laws who is on a misguided mission to wipe out the nightlife for which Mumbai has become rich and famous.

Last week the National Commission for Women (NCW). a statutory body representing the rights of women, ordered an inquiry into one of Dhoble's most notorious raids, which led to tourists being paraded in front of TV cameras and falsely branded as prostitutes.

The commission took action after being petitioned by Tehseen Poonawalla, a young entrepreneur who accuses Dhoble of "Talibanising" the city, following the raid at Mumbai's Voodoo bar in which four German women were filmed crying and telling police they were not sex workers but had simply read about the bar in their guidebook. A separate inquiry has also been ordered after dozens of partygoers were forced – apparently illegally – to give blood and urine samples following a raid in the upmarket Juhu district.

Dhoble's admirers insist he is simply carrying out orders in order to make Mumbai a nicer place to live. "He is bold, courageous and fearless," said Prashant Sharma, comparing Dhoble to Mangal Pandey, a young Brahmin soldier who in 1857 sparked a war of rebellion against the British. Sharma is a member of a group called Citizens for Better Mumbai, along with 18-year-old Shurbhi Sharma, who complains about those who "portray the police as goons and the goons as heroes". Others see more sinister powers at play.

"I think this is an attempt to divert attention away from the real problems in Mumbai, like corruption," said Vivek Bohra, a teetotal Bollywood film writer and producer, who supports the Mumbai Unite campaign, which is agitating for a modernisation of the drinking and partying legislation.

The group – run by Nisha Bedi, a gossip columnist and former Miss Mumbai, who was once stripsearched after police raided what they called a "rave party" – has drafted a petition to be sent to the chief minister of Maharashtra. It argues that Mumbai's police are misusing their powers and violating the Indian constitution, which grants all citizens "the right to life and liberty" – and with it, damaging Mumbai's "international colour and reputation".

Until the laws are changed, Mumbaikars are taking extra precautions. "I can't believe I'm having to do this," said Parveen Dusanj, a 37-year-old TV producer. But after recently getting stopped by the police on the way home from a dinner party, she felt she had no alternative. She has cleared space in her diary this week to troop down to Customs House in the south of Mumbai and hand over 1,000 rupees for a piece of paper she only recently realised she needed if she fancied a beer in a bar, or even a glass of wine at home.

Under the Bombay Prohibition Act 1949, anyone planning to consume alcohol in Mumbai needs to be in possession of a so-called "drinking permit". For most of its 60-odd years, the law was roundly ignored. Then Dhoble was made head of the city's social services unit in February 2011 and, having apparently been given a mission to check "moral bankruptcy" in society, started an energetic crackdown on any establishment falling foul of a string of laws dating back as far as the 1800s. Two raids propelled Dhoble on to the front cover of magazines, inspiring numerous spoof Twitter accounts and even a special song. First, in April, he was caught on camera wielding a hockey stick while shutting down a juice bar which he claimed was abusing the terms of its licence. Then, in May, he raided a party at the swanky Oakwood hotel, arresting 96 people, including IPL cricketers Rahul Sharma and Wayne Parnell. The sons of two state ministers were also booked. Forty-four of those arrested tested positive for drugs, according to police.

The feeling of a moral crusade intensified in June when a 55-year-old amateur chocolatier was fined under a long forgotten law which decreed that no individual was allowed to keep more than 12 units of alcohol in their own home. Mumbai's bakeries have now taken boozy cakes and rum-and-raisin chocolate bars off the shelves while they hurriedly apply for their own permits.

In another controversial case, police allegedly tried to make a 22-year-old pay 12,000 rupees (£140) after he invited some friends round to his parents' house for dinner, invoking legislation which they claimed banned anyone having guests in their home after midnight. Dhoble has been banned from talking to the press, but invites the Guardian into his windowless office for a cup of sweet cardamom tea anyway, and makes no attempt to hide the hockey stick propped up behind his desk. On the desk is a pile of bulging files held together with string containing letters from Mumbaikars reporting bars and clubs for various violations. In another room is the computer containing what he calls his "database" – a list of potential targets, which he claims runs to more than 1,000 establishments.

Before he arrived, the social services police branch that he heads up was known to conduct four or five raids per week, mostly to bust prostitution rackets and establishments that employed child labour. So far this year Dhoble has carried out 180 raids and claims to have "rescued" more than 400 women and girls and made 1,200 arrests. He would argue he has the support of all but a handful of the city's residents – and an unscientific poll carried out by the Guardian in the city centre last week suggests he is right, with nine out of 10 people saying they thought he was doing a good job.

A Blackberry held together with Sellotape rings constantly as he sits on a chair covered with a white towel and explains that he is a humble law enforcer. Not everyone sees him that way. Last month, a businessman owning the department store opposite police HQ got in trouble after hanging an enormous banner outside the building lambasting Dhoble's work. Measuring 60ft by 100ft, the banner declared in red capital letters: "WE LOVE OUR PRIVACY & OUR PARTYING. STOP PUNISHING INNOCENT REVELLERS. START PUNISHING GUILTY CRIMINALS, SIR!"

It had been up barely a week when Viren Shah, the landlord of Roopan, received a cease and desist notice from the city council. "I'm not saying everyone arrested is innocent," said Shah, "but people who are innocent should not be harassed by the police. People from all over the world come to party in Mumbai and they should not be punished for the actions of the few."Dhoble is not just cracking down on drinking and drug-taking, but also dancing. Citing another long-forgotten law, he fined bars and discos which allowed more than 10 couples on the dancefloor. Mumbai's two top clubs, Trilogy and China House, have shut while they await the numerous permits it turns out they need to ply their trade.

The owner of one upmarket bar in the Bandra area of the city said his takings had decreased by 25% in the past six weeks. "We're seeing fewer women in particular – they are frightened of being shoved in front of the TV cameras and branded as prostitutes just because they are out having a drink in a short dress," said the manager, who did not want to be named for fear of ending up on Dhoble's database. "No one wants to go out to have a good time, only to end up being subjected to blood tests and branded a whore."



India's surprise crackdowns

• In December last year, police in Ghaziabad, near Delhi, forced young men on the pull to do sit-ups as a punishment for "misleading" girls. The aim, said officers, was to "stop innocent girls from being trapped by boys with evil motives".

• Last month three young people, including two girls, were jailed for kissing drunkenly near a mall in Gurgaon, just outside Delhi. Under section 294 of the Indian penal code, it is a criminal offence if anyone commits any obscene act, sings, recites or utters any obscene words, in or near any public space.

• In the southern state of Kerala last year all schools were told to ban pupils from "cinematic dancing"; in other words, copying the raunchy moves made popular by the hit TV show Jhalak Dikhhla Jaa (India's answer to Strictly) and the racier end of Bollywood.

• Last September, a tomato-throwing festival modelled on Valencia's famous La Tomatina was banned in Bangalore and Mysore because it was deemed a waste of food and "against Indian culture".