As India's government took the oath of office at the presidential palace flanked by honour guards, a fleeting sight was spotted -- a leopard-like animal seemingly prowling past.

The animal was seen crossing through the highly guarded palace in the heart of the capital New Delhi, moving within a whisker of red carpeted steps just above where scores of India's newly elected lawmakers sat, including Prime Minster Narendra Modi.

Apparently unnoticed at the time, as the soldiers stood at attention and a lawmaker signed documents after swearing allegiance to the constitution, the creature was highlighted by eagle-eyed viewers online.

Local broadcaster NDTV called the animal "mysterious", posting a viral clip of the sandy-coloured beast taken from footage of the event screened live on Indian television Sunday evening.

It was seen for less than four seconds on screen, moving in the shadows and making it hard to identify spots, stripes or other markings.

A crowd of thousands including South Asian heads of state attended the ceremony at the Rashtrapati Bhavan palace in Delhi, and millions more watched live on television.

But India's media on Monday was divided on the long-tailed animal.

The Hindustan Times described it as "a four-legged furry friend".

The Times of India hedged its bets and called it a "cat-like creature".

But the paper also quoted an unnamed official from the Delhi forest and wildlife department who said they thought "the animal looks like a dog or cat".

Street dogs and cats are common in Delhi, but not of the apparent size seen on the video.

Leopards too are occasionally spotted in wilder corners on the outskirts of the city.

The sprawling grounds of the presidential palace abut the Delhi Ridge forest, a thick tangled park.

Rapid development has largely isolated the Ridge forest, but it was traditionally an extension of the Aravalli hills.

The rugged range runs for hundreds of kilometres south into Rajasthan, home to tigers in reserves.

There are no cheetahs in Delhi.

The last Asiatic cheetah to roam the sub-continent was believed to have been hunted down in 1947 by an Indian prince.

Last year, cheetahs brought from Namibia were released into the wild in Kuno National Park, a wildlife sanctuary in central India.