Amritpal Singh, a self-styled preacher whose calls for Sikh independence infuriated Indian authorities, has reportedly been detained in Punjab state, according to police.
After eluding capture in Punjab on March 18 he had been missing for more than a month.
He and his supporters are said to have assaulted police officers and attempted murder.
On Twitter, Punjab Police announced the arrest and issued a peace request.
After hundreds of his fans stormed a police station in February and demanded the release of an aide who had been detained, Mr. Singh quickly gained notoriety.
His campaign brought back memories of the separatist uprising and ensuing crackdown in Punjab in the 1980s, which resulted in thousands of deaths.
The search for Mr. Singh included the northern Indian states of Punjab, Haryana, Uttar Pradesh, and Uttarakhand as well as the capital city of Delhi. At India's request, Nepal also added him to their list of those under monitoring.
