Brendan Rodgers is planning a summer clearout at Anfield and Amoo has been deemed surplus to requirements by the Reds boss.
The 20-year-old was shipped off to Tynecastle on loan in January and has caught the eye in his short time with the Edinburgh club after scoring three goals in eight games.
Its thought the 6ft 5in striker will be allowed to leave the Premier League side for a fee in the region of £2million and that has alerted Celtic boss Neil Lennon.
With the reigning Scottish champions resigned to losing Gary Hooper at the end of the season, Lennon is starting his search for a new forward early and has reportedly earmarked Ngoo as a potential replacement.
Norwich are expected to revive their interest in Hooper after having six bids for the prolific 25-year-old rebuffed by the Bhoys in the latest transfer window.
Liverpool, meanwhile, have taken 18-year-old Dulwich Hamlet striker Daniel Carr on trial after becoming aware of his goalscoring exploits in the Ryman Southern League.
Carr, who used to play for Reading’s academy, has found the net 20 times this season and is the latest in a long line of talent to be plucked from the club.