By Asit Jolly BBC reporter in Chandigarh

Waters believed to be holy at Amritsar's Golden Temple in the northern Indian state of Punjab are to be cleaned up using a filtering system.

For millions of Sikhs, the pool surrounding the sanctum sanctorum of the temple, Sikhism's holiest shrine, is literally "nectar of the gods".

Many devotees come to the area from around the world

For centuries, thousands of devotees visiting the shrine have taken a dip, and many drink the water in the belief it will wash away their sins.

The city of Amritsar, which grew around the Golden Temple several centuries ago, also derives its name from the Amrit Sarowar or "pool of nectar".

Now, hundreds of years after the Sarowar was first filled with water, the custodians of the Golden Temple have decided to bring in American technology to purify the waters.

Huge cost

A religious leader responsible for the maintenance of the Sarowar, Baba Amrik Singh, told the BBC that plans were in place to install a state-of-the-art filtration and water-treatment system to clean every drop of the 31,000 million gallons of water surrounding the temple.

According to him, the canal waters supplied to several other nearby shrines will also be similarly treated before being released into the temple tanks.

A group of North American engineers recently completed designing the water-treatment system after carrying out a detailed survey of the current water supply and distribution system.

Baba Amrik Singh said the work is expected to be complete within a few months, and following this, the waters of the Sarowar will match American drinking water standards and will be cleaner than that available as bottled mineral water.

Although a closely guarded secret, the cost of this venture is expected to be huge.

But Baba Amrik Singh is confident that devotees will freely contribute and that there will be no shortage of funds.

A large chunk of the costs have already been assured by a family of US-based expatriate Sikhs.