Warraich announced his decision of joining the party at PTI Chairman Imran Khan's residence in Bani Gala on Friday.
Welcoming Warraich's decision, Khan said his inclusion in the party would strengthen the PTI in Gujranwala division.
Taking a dig at Pakistan Prime Minister Nawaz Sharif, the PTI chief said the premier should resign from his post as his family's offshore assets were being investigated by a Supreme Court appointed joint investigation team (JIT).
He said the JIT members must not feel threatened or worried due the threats being hurled at them as the people of the country are with them.
"The people of Pakistan haven't given anybody a mandate to indulge in corruption and money laundering. This nation is in debt because of the ongoing corruption and money laundering," The Express Tribune quoted Khan, as saying.
He termed the Qatari prince's letter produced in the Panama Papers as a fraud.
Khan alleged that Sharif did not produce the letter for eight months and suddenly came up with it after his address in the parliament.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)