Today, things could not be more different. At just five months, Knut the polar bear has become an international celebrity . . . and a highly profitable one at that.

Written about in newspapers across the globe, Knut merchandise is selling like hot cakes and his portrait, shot by none other than Annie Leibovitz, is due to appear alongside Leonardo DiCaprio's on the cover of next month's Vanity Fair.

It seems everyone wants to cash in on Berlin Zoo's newest celebrity.

Stuffed Knuts, Knut t-shirts, DVDs, mugs, keychains, rucksacks: these are just some of the products that have sprung up both in Germany and on the internet thanks to wily entrepreneurs hoping to cash in on "Knutmania".

Meanwhile, Haribo, the sweets firm, has even announced that it will release a raspberry-flavoured Knut marshmallow sweet in stores across Germany and Austria next week.

Dubbed Knut the Cute, the cub came to fame in March when a row erupted over comments made by an animal-rights activist who suggested he should have been put down following his mother's rejection.

The campaigner Frank Albrecht said in the German tabloid Bild that keeping him alive violated animalprotection legislation. "If truth be told, the zoo should have killed the bear." The comments provoked both outrage and a wave of public sympathy. Knut was immediately adopted by his home city as newspapers and TV stations celebrated the birth of the first polar bear to have been born in captivity in Berlin Zoo for more than 30 years.

When he made his first foray into the limelight in March, some 400 journalists from across the globe turned out to witness it. Proving himself a natural performer, he tumbled, rolled and yawned his way to instant stardom.

But few could have predicted the sheer volume of business that has been generated from Knut, who has even managed to make his presence felt on the German stock market. This week, shares in Berlin Zoo's stock more than doubled.

The number of visitors to the zoo has risen dramatically, too. In March the figure reached 200,000 . . . double the norm for that month. Every day, some 15,000 people jostle to catch a glimpse of the zoo's latest star and staff are bracing themselves for a record attendance this weekend.

Entrepreneurs and businesses have been quick to capitalise on the obvious commercial opportunities that Knutmania is providing. The German toy-maker Steiff has created a special collection of stuffed Knut bears, having struck a deal to invest part of the profits back into projects at the zoo. The teddy bears come in three sizes and cost from 19.95 to 29.95. According to Gerald Uhlich, sales director for the company, around 800 are being sold every day.

Meanwhile, the German environment minister has announced his intention to adopt the cub under the zoo's sponsorship scheme. He says he intends to use Knut as the mascot for an international conference on climate change to be held in the German capital next year.