The mystery surrounding Nidhi, the 'friend' and co-passenger of Anjali Singh, who was hit by a car and then dragged for about 12 km in Delhi's Kanjhawala area, continues to deepen.It has now emerged that Nidhi, the only eye witness in the hit-and-run case, was earlier arrested in a drug smuggling case.IANS, quoting police sources, reported that Nidhi was intercepted at the Agra railway station for bringing drugs from Telangana, after which Nidhi was arrested. Earlier, it was said that she had no previous police record.