Britain's Princess Diana's memorial fountain has turned into a "swamp" full of green slime. Visitors to the attraction in London's Hyde Park were shocked and disappointed to see the algae-like goo ruining the effect of the $10.2 million granite feature.

A spokesman for the fountain claimed the slime was not algae, but stray leaves.

The memorial - erected in tribute to Princess Diana who died tragically in a Paris car crash in 1997 - has been plagued with problems since it was opened in 2004.

Just a month after Queen Elizabeth officially opened the feature, it suffered flooding due to fallen leaves blocking the drains. Weeks later, officials were forced to close the fountain after three people slipped and were injured. The fountain opened soon after but with strict rules restricting walking in the pool.

In January 2005, the fountain was closed for five months so remedial work could be carried out.

Earlier this week, it was revealed that almost $386,844 was spent on the memorial last year, almost half of which was on security and cleaning.