CAMPAIGNERS leading the search for a botanist who disappeared in Vietnam last year have welcomed calls from the First Minister for the hunt to be stepped up.

Supporters of Jamie Taggart, 42, who runs the world-renowned Linn Botanic Gardens at Cove, Argyll and Bute, have been pushing for more information after the official search was called off in March.

However, friends and family of Mr Taggart have raised thousands of pounds to fund a continued private search in the north Vietnamese jungle but there have been few sightings of him after he left his boarding house to search for plants.

His mother Jill Mary has said she believes one possibility is that is perhaps being held captive in a jail in the region. She added: "I still believe my son is alive. Even if he has chosen to disappear there must be some evidence of that choice."

The Scottish Government has now contacted Foreign Secretary , William Hague about the case.

Campaigner Jane White said she had been contacted by Alex Salmond after she appealed for help. She said: "[Mr Salmond] said the Scottish Government have registered their interest and concerns with the Foreign and Commonwealth Office and he has also written to William Hague to highlight the case and urge for further investigations to see if more can be done."

Convenor of the Scottish Green Party, Patrick Harvie, has also written to the FCO. He wrote: "I understand that the search for Mr Taggart was reported as being abandoned earlier this year. As I am sure you will understand, this is causing Mr Taggart's relatives significant distress.

"I would therefore request an update on what the Foreign Office is doing to locate Mr Taggart, and urge that efforts to find him are redoubled."

Mr Taggart's father has also been pressing the UK Government for more information as he has tried to piece together the events after his son left his boarding house in the town of Sa Pa to search for rare plants on October 31. He left the town on a motorbike taxi heading towards the Hoang Lien National Park.

The Taggart family enlisted the help of Phil Hoolihan, a British ex-pat with knowledge of the area, and were also seeking assistance from a local private detective.

The search covered three routes that Mr Taggart may have taken - from Tram Ton to Cong Troi (Heaven's Gate), Lai Chau and Khoang Village - and took place over several months as it was hampered by poor conditions.

Mr Taggart knew the area and was last in Vietnam in 2011.

The gardens at Cove run by Mr Taggart were founded by his 82-year-old father Dr Jim Taggart, one of the most prominent botanists in Scotland.

It is thought Mr Taggart may have been going to study plants at a greater altitude than he had done before. His passport and rucksack were left behind at his guest house and only recently have arrangements been made for their return.

A spokesman for the FCO said it could not discuss details of individual cases but added: "We continue to provide consular assistance to their family at this difficult time."

The FCO has provided the family with all information passed by the Vietnamese authorities.