Toronto police have charged the man they believe is the phantom poo thrower responsible for flinging faeces at university students over the past week.

The attacks unfolded late last week and earlier this week on the University of Toronto campus at Robarts Library, at York University's Scott Library and in an area of downtown Toronto frequented by students.

On Tuesday night Toronto police announced they had arrested 23-year-old Toronto man Samuel Opoku over the attacks.

He has been charged with five counts of assault with a weapon and five counts of mischief, interfering with property.

Police say that on Friday Opoku walked into the Robarts Library and dumped a bucket of what police have described as "liquefied faecal matter" on a woman and youth sitting at a table.

Then, on Sunday, they allege Opoku walked into Scott Library and dropped another bucket of "liquefied faecal matter" over another pair of students.

A third incident occurred late on Monday night on a nearby street.

All up, police allege five people were assaulted in the attacks.

More on 7NEWS.com.au

Opoku appeared in court on Wednesday morning (local time) and has been remanded in custody for another appearance next week.

No motive has been mooted for the alleged assaults.

In a CCTV image released by police before Opoku's arrest, he is seen holding a clipboard and wearing a yellow hard hat.

However no reason has been given as to nature of his attire.

Toronto mayor John Tory congratulated police on the arrest.

"I hope this arrest will help calm concern on campuses and across the city," he tweeted.