PPP leader Dr Asim Hussain, a close aide of former president Asif Zardari, left for London on Sunday to undergo medical treatment.

Dr Hussain, who is facing corruption references and had been imprisoned for allegedly treating and harbouring terrorists at his hospital, was permitted to travel abroad for medical treatment for a month by the apex court, which ordered the removal of his name from the Exit Control List (ECL) on Aug 29 against a surety of Rs6 million.

PPP Sindh General Secretary Waqar Mehdi confirmed that Dr Hussain had travelled to London for medical treatment with the court's permission and would return within 20-25 days.

The former minister has reportedly been undergoing treatment for a cardiovascular ailment, and the Supreme Court had exempted Dr Hussain from appearing in person before the court in connection with the case pending against him. The trial will, however, continue in his absence.

In its order, the apex court bench had directed that Dr Hussain's name should be placed on the list once he returns to Pakistan.

Hussain was released from prison on the orders of the Sindh High Court in March after spending 19 months in detention.

He had been booked on the complaint of Rangers for allegedly treating and harbouring suspected terrorists at the North Nazimabad and Clifton branches of his hospital at the behest of some MQM and PPP leaders.

Corruption references had also been filed against the former minister by the National Accountability Bureau (NAB) for allegedly causing massive losses to the national exchequer through corrupt practices.