ISLAMABAD (AP) — A spokesman says Pakistan's prime minister is due to undergo open heart surgery in London next week.

Mohyuddin Wani, a spokesman for Nawaz Sharif, said Friday that the prime minister will undergo surgery Tuesday and is expected to remain in hospital for a week at least.

He did not comment on Sharif's current condition, adding only that he had experienced "complications" following a previous heart operation.

In Pakistan, Sharif is facing pressure from the opposition to conduct a thorough probe into the so-called Panama Papers, leaked legal documents that reveal that members of his family own undeclared offshore companies and expensive property in London. Some leaders have demanded Sharif step down.