A firm favourite of Britain's ever-increasing band of curry lovers, chicken tikka masala is nonetheless an unknown quantity in authentic Indian cuisine.

It was created to cater for the delicate British palate - and now the demands of UK tourists have led hotels in Bombay and Dhaka to put the dish on their menus.

And there are also reports that the balti - which is thought to originate in Birmingham - is also starting to appear on the sub-continent.

Until recently, tikka masala was an unknown quantity in Bombay

Author Shrabani Basu, whose book Curry in the Crown examines the growth of curry houses in Britain, was horrified to find the invasion of anglo-Indian dishes in India.

One in seven diners in Indian restaurants in the UK are said opt for chicken tikka masala - and 1.1m packets of the Sainsbury's version are sold each year.

And at the Tanjore restaurant at the Taj Mahal Hotel in Bombay, staff confirmed that the dish was popular in India.

"It is made with tomato and onion gravy," one member of staff told BBC News Online. "It is spicy, but not hot."

George Dorgan, editor of Tandoori magazine, said it was "definitely a British dish".

Theories abound as to how it came into existence, but it is thought that tomato paste or soup was combined with cream to satisfy the demands of a British diner who wanted gravy with his chicken tikka.

Mr Dorgan said: "There are six or seven people who claim to have invented it.

"One man made so much money selling it in Britain that he moved back to Bangladesh and started serving it there - and he still is."

Mr Dorgan said most recipes for the dish, which sometimes has a bright orange appearance, were variations on the same theme.

He said: "It is not surprising that people in India would be curious about it.

Earlier this year, Burger King introduced a "Masala Burger"

"They are bound to ask: 'What is this chicken tikka masala? What part of India does it come from?'"

But he said the demand was really coming from British tourists looking for the Indian dishes they were used to.

As for its popularity in the UK, Mr Dorgan said: "It gives hint of things that are spicy, but it is not a dish which will scare away the spice-shy.

Mr Dorgan said many dishes on sale in the UK's Indian restaurants, including favourites such as madras and jalfrezi, were variations of the authentic recipes found in India.

He said: "The whole standard repertoire has been adapted to meet a perceived British palate, but British tastes are becoming more sophisticated and more restaurants are stating to accommodate both authentic Indian food and anglo-Indian dishes."

The curry can now claim to be the UK's national dish, with approximately 8,000 curry houses employing 70,000 people.