Faisal, the son of philanthropist Abdul Sattar Edhi, had last week met Khan and handed over a cheque of Rs 10 million for the Prime Minister's coronavirus relief fund.
A picture posted by Imran Khan's party, Pakistan Tehreek-e-Insaf (PTI) from its Twitter handle on April 15 shows Faisal handing over the cheque to Pakistan Prime Minister.
According to Dawn, Faisal later told a channel that he along with two industrialists were with Khan for "six to seven minutes."
Normally, once someone tests positive for coronavirus, all who came in contact with him are isolated and quarantined so as to curb the spread of the virus.
Faisal's son, Saad Edhi, was quoted as saying that his father started developing symptoms soon after he travelled to Islamabad.
"The symptoms lasted for four days before subsiding," Saad was quoted as saying by Dawn.
Soon after, the Edhi Foundation Chairman got tested for COVID-19 and the results came as positive on Tuesday. Faisal said he has been directed to self-isolate for next week.
The Prime Minister's Personal Physician, Dr Faisal Sultan, also Shaukat Khanum Memorial Cancer Hospital CEO said Khan was occupied with a cabinet meeting and that he will recommend him to get tested.
"As soon as he is finished, I will meet him and recommend that he gets tested. We will follow all protocols in place and make recommendations accordingly," he said.
According to the latest information, coronavirus cases in Pakistan have risen to 9505 with 197 deaths so far.
( With inputs from ANI )