A riddle worthy of a detective novel – involving an internationally acclaimed violinist, her prized instrument stolen at a busy London station, and a false trail leading to Bulgaria – may be nearing its conclusion.

The discovery by police of a 1696 Stradivarius worth £1.2m and two bows with a combined value of £67,000 taken by opportunist thieves in 2010 while Korean-born violinist Min-Jin Kym was eating at a Pret a Manger cafe at Euston station has, she said, left her "on cloud nine" with an "incredible feeling of elation".

Kim, 35, said in a British Transport police video: "This had been the instrument I had been playing on since I was a teenager, so it was a huge part of my identity for very many years."

The theft prompted a public appeal for help and the release of CCTV on BBC's Crimewatch. John Maughan was jailed for four and a half years at Blackfriars crown court for the theft in 2011. He and two accomplices had tried to sell it for £100 in an internet cafe not far from Euston. Two teenagers were also sentenced for their involvement.

Earlier this year, investigations into reports that the violin may have been found in Bulgaria discovered that the instrument involved was merely a replica training instrument made no more than 100 years ago.

Now, however, experts are satisfied that the real thing and the two bows – a £62,000 Peccatte bow and a £5,000 bow made by the School of Bazin – have been recovered from a property in the Midlands, and are intact with some "very minor" damage. The police are not releasing further details.

Kym said: "It's been a very difficult journey; I still can't quite believe quite what has happened.

"The loss of the instrument, and the acute responsibility I felt, was always at the back of my mind at every moment of the day.

"The theft was a crushing blow and the detectives in the case had always, quite rightly, been very careful not to give me false hope. When they told me the good news, it didn't feel real."

Detective Chief Inspector Simon Taylor of British Transport police said: "We're absolutely delighted to have recovered the Stradivarius violin after a long and very complex investigation. Though it took some time to successfully locate and recover the violin, we were confident it had remained in the UK.

"I always maintained that its rarity and distinctiveness would make any attempt to sell it extremely difficult, if not futile, because established arts and antiques dealers would easily recognise it as stolen property."

Louise Deacon, assistant manager of musical instruments at insurance group Lark, said: "We are really happy to have such a valuable and treasured instrument back in the world of classical music where it belongs.

"We are looking forward to the outcome of our experts' assessment on the condition of the instrument so we can then liaise with Ms Kym with regards to purchasing back the Stradivari."

A spokesman from Lloyd's insurer, Canopius, said: "For Min-Jin Kym, her violin is priceless and insuring it against theft can never reflect the emotional cost of her loss. It's great news that the violin has been found."