  The evolution of asymptotic giant branch stars from the spherical symmetry
into the diverse shapes of planetary nebulae (PNe) is a topic of intensive
research. Young PNe provide a unique opportunity to characterize the onset of
this transitional phase. In particular, OH maser-emitting PNe (OHPNe) are
considered nascent PNe. In fact, only 6 OHPNe have been confirmed to date. In
order to identify and characterize more OHPNe, we processed the unpublished
continuum data of the interferometric follow-up of the Southern Parkes
Large-Area Survey in Hydroxyl (SPLASH). We then matched the interferometric
positions of OH maser and radio continuum emission, considering the latter as a
possible tracer of free-free emission from photoionized gas, characteristic of
PNe. We report 8 objects with a positive coincidence, 4 of which are classified
as candidate OHPNe here for the first time (IRAS 16372-4808, IRAS 17494-2645,
IRAS 18019-2216 and OH 341.6811+00.2634). Available evidence strongly indicates
that they are evolved stars, while the comparison with confirmed OHPNe
indicates that they are likely to be PNe. Their final confirmation as bona fide
PNe, however, requires optical/infrared spectroscopy. The obtained spectral
indices of the radio continuum emission (between $\simeq$ 0.4 - 1.3) are
consistent with partially optically thick free-free emission from photoionized
gas. Also, they cluster in the same region of a WISE colour-colour diagram as
that of the confirmed OHPNe ($9.5 \lesssim [3.4]-[22] \lesssim 13.5$, and $4.0
\lesssim [4.6]-[12] \lesssim 7.0$), thus this diagram could help to identify
more OHPNe candidates in the future.
