Five Canadian diplomats and members of their families who fell victim to mysterious health complaints while posted to Cuba are suing the government for 28 million Canadian dollars ($21.1million) in damages.
The group of 14 said Ottawa delayed their evacuation from Havana and their medical treatment. Last year, Canadian and US officials were recalled from Havana after complaining of dizziness and migraines.
Despite being back in Canada for over 18 months, they said they all still suffer from what they called "Havana Syndrome", Canadian broadcaster CBC reported on Wednesday. They said they began experiencing symptoms of this syndrome in spring 2017.
The causes of their illness were not known, but Canada discounted the idea of a "sonic attack" on its Embassy, reports say.
According to the broadcaster, several families were subsequently moved from Havana, but until April 2018 Canada continued to post new staff to Cuba despite warnings from US counterparts.
"Throughout the crisis, Canada downplayed the seriousness of the situation, hoarded and concealed critical health and safety information and gave false, misleading and incomplete information to diplomatic staff," the diplomats said in a statement.
"My wife, she isn't the same anymore," one unnamed diplomat told CBC, adding that "she has gaps in her memory, headaches, problems hearing".
"She picks up the telephone to make a call but forgets why, enters rooms without reason. She can't concentrate anymore," the diplomat said.
Another diplomat and a young mother taking part in the lawsuit, said she suffers from migraines and excessive fatigue. She said she has become very sensitive to light and needs to wear sunglasses in her own home.
Washington withdrew most of its non-essential personnel from Cuba in September 2017 and said 21 embassy employees had been affected.
Last month, Canada said it would be cutting its embassy staff by up to half.
The affected Canadian diplomats were being monitored by the University of Ottawa's Brain and Mind Research Institute and the Brain Repair Centre at Dalhousie University in Nova Scotia, CBC said.
Meanwhile, at a news conference in Washington, Canada's Foreign Affairs Minister Chrystia Freeland said she was aware of the lawsuit.
"I... want to reiterate that I have met with some of these diplomats and, as I said to them, their health and safety needs to be our priority."
Cuba has repeatedly denied any involvement in the incident.