'His leadership was immensely popular and led to a dramatic general election result in 2001'
(Getty)
Further tests are needed to find out the cause of Charles Kennedy's death, police have said.
The former leader of the Liberal Democrats died at his home in Fort William in the Highlands earlier this week, aged just 55.
Police said there were no suspicious circumstances surrounding his death but having carried out an initial postmortem, they said more checks were now required.
A spokeswoman for Police Scotland said: "We can confirm that further tests are being carried out to establish the cause of death.
"It remains a sudden and non-suspicious death and the Procurator Fiscal will be sent a report."
Charles Kennedy - his political career in pictures
David Cameron hailed Mr Kennedy for representing the “best that politics can be” and praised him for his principled stand against the Iraq War.
Donald sat in the viewing gallery with his mother, Sarah Gurling, who was married to Mr Kennedy for seven years before the couple divorced in 2010.
Nick Clegg, who stood down as Lib Dem leader after last month’s crushing election result, described Mr Kennedy as a "fully signed up member of the human race" in a touching tribute to his former colleague.
Nick Clegg pays tribute to his predecessor Charles Kennedy
(PA)
He added the former party leader was the "polar opposite of a cardboard cut-out, points-scoring party politician."
In a particularly emotional moment, Lib Dem leadership favourite Tim Farron looked up to Donald sitting in the gallery and said: "It's not what you have done, it is who you are.
"And Charles Kennedy was a very special man. Donald you should be really proud of your daddy, I am proud of your daddy, I loved him to bits. I am proud to call him my friend," he added, close to tears.
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