The arrest of any person in a cognizable case which doesn’t involve violent crimes, such as Section 498A, is illegal per Indian law. Due to beliefs propagated by the police, lawyers, and abetted by moronic magistrates, hundreds of thousands, across India, have been arrested under Section 498A. Fortunately, changes have been introduced in the penal code through the CrPC amendments which have ended this practice.
Some police depts have also taken steps to end the practice of arresting people on the the filing of a 498A complaint. Here’s a copy of one such circular sent by the office of the DGP of AP to most districts in the state of Andhra Pradesh: