Further tests are to be carried out to determine the cause of Charles Kennedy’s death.
The former Liberal Democrat leader died suddenly at his home in Fort William on Monday.
Police Scotland said there were no suspicious circumstances and that a post-mortem examination would be carried out but it has now been reported that further tests are needed.
A spokeswoman for Police Scotland told the Daily Record: “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.”
Tributes have been paid to Mr Kennedy from across the political spectrum.
His ex-wife, Sarah, and 10-year-old son Donald attended a special session in the House of Commons yesterday where MPs paid their respects.
Prime Minister David Cameron called Mr Kennedy the “most human of politicians” and - at his best - “the best that politics can be”.
MPs shared their memories of the ex-Highland MP’s “courageous” opposition to the Iraq War, his compassion, his humour and his ability to connect with people of all backgrounds.
Outgoing Lib Dem leader Nick Clegg called his predecessor a “formidable parliamentarian” but said Mr Kennedy had been much more than his politics.
He spoke of the ‘’enduring humanity” in Mr Kennedy, adding that he was the “polar opposite of a cardboard cut-out, point-scoring party politician”.
Labour’s Tom Watson spoke directly to Mr Kennedy’s son, saying: “Your father was a very great man. He stood up for what he believed in, he led a party of the centre-left with dignity and compassion and when you are older you will know your mum and dad believed in a cause greater than themselves and you will be proud.”