Mbombo departs Zesco after 16 months with the Ndola club whom he guided to the 2016 Barclays Cup title following a 1-0 win over Zanaco.
Club sources have revealed that Mbombo is headed for an unnamed club in Saudi Arabia.
The DR Congo-born striker was conspicuously missing from Saturday’s 2-0 home win over Nkwazi.
Mbombo joined Zesco on a permanent move in 2017 after an initial 12-month loan spell with the Ndola club from Kabwe Warriors.
He leaves Zesco with four competitive goals this season of which one came in the 2017 CAF Confederation Cup.
He was Zesco’s top scorer in the 2016 CAF Champions League with 5 goals and scored another 9 in the league last term.