A Belgian under-21 international, Lukebakio spent last season at another Bundesliga side in Fortuna Dusseldorf where he was a star.
Lukebakio scored 14 goals and provided five assists in all competitions and his performances attracted interest from a number of sides in Europe.
Ligue 1 runners-up Lille were keen on Lukebakio according to the report but the French outfit were only able to offer £11m with bonuses worth £2.75m. This was nowhere near Watford's valuation of the versatile forward and Hertha Berlin's financial power was too much for Lille despite being able to offer Champions League football.
Lukebakio was touted as a replacement for Lille's top scorer from last season Nicolas Pepe, who is close to securing a move to Watford's Premier League rivals Arsenal. Lukebakio will now head to the German capital according to the report where he will sign a five-year contract with Hertha in the coming days.
Over £18m for a player who has played just 15 minutes of first-team football is a remarkable bit of business by the Hornets.
Manager Javi Gracia can now reinvest the money they will get for the Belgian to strengthen other areas of the squad as they head into the new Premier League season in less than two weeks.
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