A strong emission line at 6703Åhas been detected in the optical spectrum for the host galaxy ( R=23.1 ) of the radio source RC J0311+0507 ( 4C+04.11 ) .
This radio galaxy , with a spectral index of 1.31 in the frequency range 365–4850 MHz , is one of the ultrasteep spectrum objects from the deep survey of a sky strip conducted with RATAN-600 in 1980–1981 .
We present arguments in favor of the identification of this line with Ly \alpha at redshift z = 4.514 .
In this case , the object belongs to the group of extremely distant radio galaxies of ultrahigh radio luminosity ( P _ { 1400 } = 1.3 \times 10 ^ { 29 } WHz ^ { -1 } ) .
Such power can be provided only by a fairly massive black hole ( \sim 10 ^ { 9 } M _ { \hbox { $ \odot$ } } ) that formed in a time less than the age of the Universe at the observed z ( 1.3 Gyr ) or had a primordial origin .

Key words : radio sources , radio galaxies , black holes