The artist behind 2002’s second best-selling album, Nellyville, had planned to play next month in London; Cardiff, Wales; Sheffield and Manchester in northern England; Birmingham in central England; Belfast, Northern Ireland and Dublin, Ireland.

He was to perform with fellow rapper Eve, who had a recent hit with “Satisfaction.”

“Unfortunately, Nelly has had to postpone the tour due to an unforeseeable personal matter,” his promoter Clear Channel said in a statement.

It did not specify what the problem was, but Britain’s Press Association news agency said there was an illness in the rapper’s family.

Concert organizers told fans they could keep their tickets to use at the rescheduled shows or return them for a refund.

Nelly’s biggest hits include “Hot in Herre” and “Dilemma.” He garnered Grammy nominations for both album and record of the year.