  A tiny fraction of observed gamma-ray bursts (GRBs) may be lensed. The time
delays induced by the gravitational lensing are milliseconds to seconds if the
point lenses are intermediate-mass black holes. The prompt emission of the
lensed GRBs, in principle, should have repeated pulses with identical light
curves and spectra but different fluxes and slightly offset positions. In this
work, we search for such candidates within the GRBs detected by Fermi/GBM,
Swift/BAT, and HXMT/HE and report the identification of an attractive event GRB
200716C that consists of two pulses. Both the autocorrelation analysis and the
Bayesian inference of the prompt emission light curve are in favor of the
gravitational lensing scenario. Moreover, the spectral properties of the two
pulses are rather similar and follow the so-called Amati relation of short GRBs
rather than long duration bursts. The measured flux ratios between the two
pulses are nearly constant in all channels, as expected from gravitational
lensing. We therefore suggest that the long duration burst GRB 200716C was a
short event being lensed. The redshifted mass of the lens was estimated to be
$4.25^{+2.46}_{-1.36}$ $\times$ $10^5$ $M_{\odot}$ (90$\%$ credibility). If
correct, this could point towards the existence of an intermediate-mass black
hole along the line of sight of GRB 200716C.
