He was also the resident pharmacist between June 2014 and October 2015.
His offending, which he said took place over a period of 10 years, was discovered by an employee of the pharmacy's document destruction service.
After being notified, police found hard copy images of child pornography.
When other employees had left, Allen would access the pharmacy's computer and printer and print the images.
He would then store the photos behind a cupboard in the pharmacy's office until later throwing them in the rubbish.
Allen admitted he would print about 12 images, two or three times per week.
Acting on behalf of the Professional Conduct Committee (PCC) at the disciplinary hearing, Ms M Neill told the tribunal, chaired by Kenneth Johnston QC, that the images involved were at "the more serious end of the spectrum".
"The victims were children and therefore peculiarly vulnerable."
She emphasised the Pharmacy Code Conduct of Ethics, which requires pharmacists to "act in a manner that promotes public trust and confidence ... and enhances the reputation of the profession".
In reaching its conclusions to cancel the registration, the tribunal said Allen's offending was "extremely serious".
"The seriousness of the offending, and his breach of his legal, professional and
moral obligations, not only calls into question the practitioner's fitness to
practice, but, inevitably, has brought disrepute to the pharmacy profession as a
whole," they said.
"There is an important public safety aspect to this case ... the tribunal has concluded that the protection of the public must be considered."
The tribunal said it doubted Allen would reoffend but "our perception is that if the practitioner were permitted to retain his registration in the face of these convictions, the public's confidence in the profession would be seriously compromised".
The Professional Conduct Committee sought the usual costs of 50 per cent of the hearing and findings. The total costs for the tribunal and PCC in the matter were more than $20,000.
However, the tribunal was "reluctant" to make an order which would "almost inevitably lead to [Allen's] bankruptcy and ordered him to pay $500 towards the PCC's costs.
Allen has not worked as a pharmacist since October 2015 and currently works for the minimum wage in garden maintenance.
He has undertaken a voluntarily six-month treatment programme since his conviction.