One of Bollywood's most eagerly awaited films has been dragged into a fierce legal battle, amid allegations that it owes just a little too much to a certain boy wizard.

The Bombay-based producer of Hari Puttar: A Comedy of Terrors is being sued by Warner Bros, the Hollywood studio behind the hugely successful Harry Potter franchise. Hari, the lawsuit alleges, is too close to J.K.Rowling's Harry for comfort.

The Hindi-language children's film, which was shot entirely on the Yorkshire Dales in 2006 and 2007 on a budget of £2 million, tells the story of Hari Prasad Dhoonda, a hapless ten-year-old Punjabi loner who is nicknamed Hari Puttar and moves to Britain.

The plot tells how Hari's father, Professor Dhoonda - and Warner's lawyers may have noted that their client's films feature a Professor Dumbledore - is assigned to work on a top-secret project for the Indian Army. His plans are kept on a computer chip hidden in the family's house.

A series of mishaps results in Hari, who possesses no magic powers, being left home alone when the family departs on holiday. It transpires that an infamous underworld don, Kali Mirchi, has assigned two bungling thugs to steal the secret chip. It is up to Hari to save the chip - and the world.

If the plot brings to mind another film involving a young boy left behind by his family who has to thwart a couple of crooks - Home Alone, the 1990 hit staring Macaulay Culkin - it probably isn't bothering the Indians, who are dismissing claims of plagiarism. Mirchi Movies, the production house behind Hari Puttar, says that any similarity with Ms Rowling's hero is purely coincidental. “Personally, I cannot see any resemblance between the names,” Munish Purii, the chief executive of the company, told The Times. “Hari” was a popular boys' name in India, while “Puttar” meant son, in Punjabi, he explained.

Zain Khan, 11, the boy who plays Hari, agreed. “The movie has nothing to do with Harry Potter,” he said.

Indian pundits have speculated nevertheless that audiences may be confused. “An Indian Harry Potter. You can't think of anything else when confronted with the title Hari Puttar,” the Hindustan Times said.

This is not the first allegation that Ms Rowling's work, which has been translated into 67 languages, including Hindi, has been copied illegally. The Harry Potter brand is estimated to be worth more than £7 billion and the books have sold more than 400 million copies. Bootleggers producing everything from pirate DVDs to counterfeit lunchboxes have made a beeline for the boy wizard and the novels have frequently been leaked online before publication.

The legal action threatens to delay the release of Hari Puttar, regardless of the result. The case is being heard this week in the Bombay High Court and will be seen as a key test of India's intellectual property laws. The film is due for release in India on September 12 and had been expected to reach Britain later this year. “Our project has been in the public domain for two years. It is unfortunate that it is only now that Warner has taken action,” Mr Purii said.

Warner confirmed that it was taking legal action but refused to comment further.

The case will pit one of India's biggest media companies against some of Hollywood's fiercest lawyers. Mirchi Movies is owned by Bennett & Coleman, the privately owned company that publishes The Times of India. The company is valued at up to $25 billion (£13.5 billion). Warner Bros, owned by Time Warner, grossed about $3.4 billion last year from its films.

LEGAL PRECEDENTS

Earlier this year Rowling sued Steve Vander Ark for publishing The Harry Potter Lexicon, a 400-page reference book based on the fan website he ran.

In Harry Potter and Leopard-Walk-Up-to-Dragon, a favourite in China in 2002, Harry encountered sweet and sour rain and joined Gandalf to re-enact scenes from The Hobbit. The publishers stopped publication after Rowling threatened to sue.

Barry Trotter and the Shameless Parody, in which characters called Barry, Len and Ermine square up to Lord Valumart, was a bestseller in 2003.

Belarussian readers have been able to follow the adventures of the grenade-launcher-wielding Porri Gatter.

Harry Potter in Calcutta, in which Harry meets characters from Bengali literature, was withdrawn by its Indian publisher.

Tanya Grotter, the heroine of Tanya Grotter and the Magic Double Bass, rides a double bass, sports a mole instead of a bolt of lightning and attends the Tibidokhs School of Magic. Russian author Dmitri Yemets called his book, which sold more than a million copies, “cultural competition” for the originals.

Rowling gave her backing last year to “fan fiction” not-for-profit publications circulated on the internet.

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