New Delhi, July 29 - Prime Minister Manmohan Singh Wednesday mourned the death of Gayatri Devi, the erstwhile maharani of Jaipur who was once considered one of the world's most beautiful women, and called her a close friend and an exceptional human being.

'I convey my heartfelt condolences to her family and friends. I pray for peace of the departed soul,' The prime minister said.

He said Gayatri Devi, who was popularly known as Rajmata, was a 'close friend and an exceptional human being'.

In his message, he recalled Gayatri Devi entered politics in the 1960s and was elected to the Lok Sabha for three terms.

'In her public life she worked with devotion for the socio-economic development of her people. She was an international celebrity, named in a list of the ten most beautiful women of her time.'

'She contributed substantially to the cause of the uplift of the girl child. She also promoted the dying art of blue pottery in Rajasthan,' he said.

Gayatri Devi, 90, died Wednesday at the Jaipur-based Santokba Durlabhji Memorial Hospital (SDMH) where she was admitted Tuesday for breathing problems.