A mysterious benefactor has emerged with hundreds of unreleased Thin Lizzy songs, stored in secret since the death of frontman Phil Lynott in 1986. Universal Music will release a selection of these recordings in June, working with the full co-operation of the band's surviving members.

"This is an absolutely stunning find," Steve Hammonds, project manager for the box set, told the Irish Independent (via Brooklyn Vegan). Featuring nearly 700 songs, "[these] are out-takes, unheard versions of Thin Lizzy hits and, most exciting of all, material that was recorded but never released at the time".

It's been exactly 26 years since Lynott died, aged just 36, and almost 30 years since the original Thin Lizzy lineup split. As Lynott was dying, Hammonds explained, he entrusted 150 tapes to an unnamed third party, described as a "Thin Lizzy fan". "They held on to it for decades because they were waiting for the right people to come along," Hammonds said. "They really didn't trust anyone enough to release it properly."

That changed last year, when Universal Music released a seven-disc Thin Lizzy box set, drawn from the BBC archives. "[That] made them believe we were the right people," Hammonds said. The fan came forward with Lynott's musical cache, offering it to Universal free of charge. The label is now working with Lynott's former bandmates, including Scott Gorham, who still tours under the Thin Lizzy name. "We have been sending them tapes of what we've found and respecting their wishes as regards the material being issued and the artwork," Hammonds said.

Formed in Dublin in 1969, Thin Lizzy released 13 albums, including four UK top 10 hit singles.