The former leader’s supporters are said to have gathered outside his home with promises to “take over” if Khan is arrested.
The former cricket star lost a no-confidence vote in April and was forced to step down after just over three years in power. He has since loudly criticized the country’s government and military, and has held several mass rallies to mobilize his supporters.
The police investigation comes after Khan accused authorities of torturing one of his associates who is being held on charges of sedition.
Earlier this weekend, all television channels in Pakistan were banned from live broadcasting any speech or performance by Khan, which is said to spread hatred and lead to unrest.
One of the country’s largest private television channels, ARY News, has been shut down in large parts of the country. The government-critical channel supports Khan, which is also said to be a large part of the country’s younger generation, and his speech is often broadcast to large audiences on television as well as on social media.
Khan has previously also been banned from organizing protests in the capital Islamabad.