I think this has nothing to do with the pan leaves. This could be Pan Masala mixed with some other intoxicating products created specially to sell those who are looking some sort of intoxication. Pan Masala actually is a mouth freshner available in Indian market containing different ingredients. The ingredients in pan masala vary widely, depending on personal taste and region. Fennel seeds are often a key ingredients, since they tend to leave the mouth with a fresh feeling, and it is also possible to find cinnamon, cardamom, lime, menthol, areca nuts, betel nuts, and various other ingredients. When chewed, the ingredients in the pan masala help to freshen the breath, and they are also said to aid digestion, which can be very useful after eating ferociously spicy food which might upset the stomach.

Now a days there are variations available in India which is giving intoxication to the user and are banned in most of the Indian states. I think the pan seized by the Authorities will be something belongs to the banned category.