ISLAMABAD: Pakistan Tehreek-i-Insaf (PTI) Chairman Imran Khan and Interior Minister Chaudhry Nisar Ali Khan became the latest political leaders who reached London on Thursday, joining others from the country's political elite who have traveled abroad in the last few days.

Their arrival comes a day after Prime Minister Nawaz Sharif reached in London for what his office said is 'medical treatment', at a time when he is under fire from opposition parties for his family's off-shore accounts exposed by the Panama Papers.

Imran Khan and Nisar were boarded the same Pakistan International Airlines flight for the British capital. PTI leaders Jahangir Tareen and Aleem Khan are accompanying Imran on the flight.

Once in the UK, Imran will hold two fundraisers and a rally for Kashmir in Birmingham, events the PTI says had been scheduled months in advance.

The PTI chief will also be meeting "two companies specialising in forensic tax audits" to start an independent probe on the premier and his family after the startling revelations made in the Panama data leaks, he told reporters before his departure.

The final destination of the interior minister, however, is not the UK but Germany. Nisar at a press conference on Wednesday said he would travel to Germany for a two-day visit to seek medical treatment for his wife.