The airline used to create African budget carrier Fastjet is reported to be facing a £1 million tax claim in Tanzania.
The company was found not have paid payroll and property taxes as well as airport departure charges from January to November last year, the Daily Telegraph reported.
Fastjet was created after African conglomerate Lonrho sold its aviation division Fly540 to listed cash shell Rubicon.
EasyJet founder Sir Stelios Haji-Ioannou was brought in to add his branding and expertise.
A FastJet spokesman said: “The matter in question is a legacy issue inherited from the Fly540 operation. FastJet works closely with the Tanzanian government to properly address all historic issues relating to tax.”