Tuesday, March 1 2005 19:44 Hrs (IST) - World Time -

Ballia (UP): Police have stepped up security around the residence of Saurav Singh whose claim to have topped the young scientists discovery examination of the US space agency NASA turned out to be a hoax.

Two constables have been posted outside Saurav's house at Narhi village in Ballia, police said adding those who had used the teenager as a "tool" might try to harm him physically.

There was also the possibility of Saurav flee to evade arrest, they said.

A police team, which went to Jaipur and Kota in Rajasthan to gather evidence in the case, was in possession of a magazine that allegedly published an advertisement inviting applications for appearing in the NASA examination at London.

Police said no such advertisement was published in the magazine.