Context :

Aims : We focus on early-B type stars with helium overabundance , for which the presence of a magnetic field has not previously been reported .

Methods : The measurements were carried out using high-spectral-resolution spectropolarimetric observations obtained with the High Accuracy Radial velocity Planet Searcher ( HARPS ) in polarimetric mode , installed at the ESO La Silla 3.6m telescope .

Results : For five He-rich stars , the longitudinal magnetic field was detected for the first time .
For one target , HD 58260 , the presence of a longitudinal magnetic field of the order of 1.8 kG has already been reported in the literature , but the magnetic field has remained constant over tens of years .
Our measurement carried out using the polarimetric spectra obtained in 2015 March indicates a slight decrease of the longitudinal magnetic field strength compared to measurements reported in previous works .
A search for periodic modulation in available photometric data allowed us to confidently establish a period of 2.64119 \pm 0.00420 d in archival ASAS3 data for CPD - 27°1791 .
No period could be determined for the other five stars .

Conclusions : The obtained results support the scenario that all He-rich stars are detectably magnetic and form an extension of the Ap star phenomenon to higher temperatures .