Britain's National Crime Agency (NCA) said Friday it had launched an investigation into the deaths of 88 people in the country who bought substances to assist with suicide from Canadian websites.

"The NCA has taken the decision to conduct an investigation into potential criminal offences committed in the UK. This operation is under way," said NCA deputy director Craig Turner.

The law enforcement agency, sometimes called the UK's FBI, added that "at this early stage there are no confirmed links between the items purchased from the websites and cause of death in any of these cases".

The announcement came after Canadian Kenneth Law, 57, was arrested in Ontario in early May and charged with two counts of counselling and aiding suicide.

He is accused of selling a lethal substance to people across the world, with Canadian police alleging that he sent at least 1,200 packages to over 40 countries.

Police in the United States, Italy, Australia and New Zealand are also investigating his actions.

"It is believed that the suspect distributed and marketed the substance online to target individuals at risk of self-harm," Canadian police said in a statement.

Law made a brief court appearance on Friday and is, according to local media, scheduled to return on September 8.

In the meantime, he will remain in custody.