A metal detectorist who discovered the “richest collection” of rare Viking artefacts ever found in the UK is set to receive a reward of almost £2m.

Derek McLennan uncovered the 10th-century hoard, which includes silver bracelets and brooches, a gold ring, an enamelled Christian cross and a bird-shaped gold pin, in a Dumfries and Galloway field in 2014.

He passed it on to experts and now the body that rules on ownerless goods and property, the Queen’s and Lord Treasurer’s Remembrancer (QLTR), has ruled the 100-odd items should be allocated to National Museums Scotland (NMS) for display, provided it pays £1.98m to McLennan.

The amount is ex gratia and has been set to reflect the market value of the find.

Rules on discoveries in Scotland mean only the finder receives payment, differing from the rest of the UK where awards are split with the landowner. NMS has six months to raise the funds.

David Harvie, the QLTR, described the Galloway hoard as internationally significant and “one of the most important finds ever discovered in Scotland”.

He said: “I am pleased to announce that I am minded to accept the recommendation of the Scottish Archaeological Finds Allocation Panel [Safap] that these wonderful items be allocated to National Museums Scotland, subject to it meeting the ex gratia award which would then be payable to the finder.”

Dr Gordon Rintoul, director of NMS, said: “The Galloway hoard is of outstanding international significance and we are absolutely delighted that QLTR has decided to allocate it to NMS.

“We now have six months to raise £1.98m to acquire this unique treasure for the nation and ensure it can be enjoyed by future generations both at home and abroad.”

The bulk of the hoard is silver jewellery but it also contains textiles and an “outstanding range of exceptional precious metal and jewelled items”, including a rare gold ingot, beads, crystals and a decorated silver-gilt cup thought to be of Byzantine origin.

NMS said other finds around Britain or Ireland have been exceptional for a single type of item but the Galloway hoard was unique in bringing together a variety of objects hinting at previously unknown connections between people across Europe in the 10th century.

The Galloway Viking Hoard campaign group had been calling for the items to be displayed in the south-west of Scotland close to where they were discovered.

NMS said it supports the call and will work with Dumfries and Galloway council to have some of the hoard on display in the region.

Evelyn Silber, Safap chair, said: “The panel is grateful to the finder for reporting these stunning artefacts which include decorative glass beads, silver bracelets and brooches, a gold ring, a bird-shaped gold pin and a highly-decorated gilt vessel recognised as being one of only three known examples.

“These will now be preserved and put on display for the people of Scotland, and the world, to enjoy.

“The mysterious circumstances of their deposition and unique quality will attract researchers and enthusiasts alike.”