We report results of observations and analyses on the gamma-ray blazar PKS
1622-297, with emphasis on the COMPTEL data (0.75 - 30 MeV) collected between
April 1991 and November 1997. PKS 1622-297 was detected as a source of
gamma-rays by the EGRET experiment aboard CGRO in 1995 during a gamma-ray
outburst at energies above 100 MeV lasting for five weeks.
In this time period the blazar was significantly (~ 5.9 sigma) detected by
COMPTEL at 10-30 MeV. At lower COMPTEL energies the detection is marginal,
resulting in a hard MeV spectrum.
The combined COMPTEL/EGRET energy spectrum shows a break at MeV energies. The
broad-band spectrum (radio - gamma-rays) shows that the gamma-ray emission
dominates the overall power output. On top of the 5-week gamma-ray outburst,
EGRET detected a huge flare lasting for > 1 day. Enhanced MeV emission (10 - 30
MeV) is found near the time of this flare, suggesting a possible time delay
with respect to the emission above 100 MeV. Outside the 5-week flaring period
in 1995, we do not detect MeV emission from PKS 1622-297.