We discuss the possible source of a highly-dispersed radio transient discovered in the Parkes Multi-beam Pulsar Survey ( PMPS ) .
The pulse has a dispersion meausure of 746 \mathrm { cm } ^ { -3 } \mathrm { pc } , a peak flux density of 400 mJy for the observed pulse width of 7.8 ms , and a flat spectrum across a 288 -MHz band centred on 1374 MHz .
The flat spectrum suggests that the pulse did not originate from a pulsar , but is consistent with radio-emitting magnetar spectra .
The non-detection of subsequent bursts constrains any possible pulsar period to \gtrsim 1 s , and the pulse energy distribution to being much flatter than typical giant pulse emitting pulsars .
The burst is also consistent with the radio signal theorised from an annihilating mini black hole .
Extrapolating the PMPS detection rate , provides a limit of \Omega _ { BH } \lesssim 5 \times 10 ^ { -14 } on the density of these objects .
We investigate the consistency of these two scenarios , plus several other possible solutions , as potential explanations to the origin of the pulse , as well as for another transient with similar properties : the Lorimer Burst .