Context :

Aims : Uncovering the ingredients and the architecture of planetary systems is a very active field of research that has fuelled many new theories on giant planet formation , migration , composition , and interaction with the circumstellar environment .
We aim at discovering and studying new such systems , to further expand our knowledge of how low-mass companions form and evolve .

Methods : We obtained high-contrast H-band images of the circumstellar environment of the F5V star HD 206893 , known to host a debris disc never detected in scattered light .
These observations are part of the SPHERE High Angular Resolution Debris Disc Survey ( SHARDDS ) using the InfraRed Dual-band Imager and Spectrograph ( IRDIS ) installed on VLT/SPHERE .

Results : We report the detection of a source with a contrast of 3.6 \times 10 ^ { -5 } in the H-band , orbiting at a projected separation of 270 milliarcsecond or 10 au , corresponding to a mass in the range 24 to 73 M _ { \text { Jup } } for an age of the system in the range 0.2 to 2 Gyr .
The detection was confirmed ten months later with VLT/NaCo , ruling out a background object with no proper motion .
A faint extended emission compatible with the disc scattered light signal is also observed .

Conclusions : The detection of a low-mass companion inside a massive debris disc makes this system an analog of other young planetary systems such as \beta Pictoris , HR 8799 or HD 95086 and requires now further characterisation of both components to understand their interactions .