The Canadian mission in Sri Lanka is to reopen on Monday, a week after it closed following an anthrax scare that led to a diplomatic row.
A monk wears a new robe given by the Canadian mission
Sri Lanka complained to Canada after allegations that a group of Buddhist monks had been forced to disrobe over the incident.
The Canadian High Commission in Colombo denied the charge.
The mission was shut down after fears that white powder on one of the monks' passports might be anthrax.
It later turned out to be talcum powder doubling as insect repellent.
Canada has denied forcing the monks to disrobe, saying they had willingly complied with security regulations.
But Sri Lanka's main opposition UNP joined the growing protest over the incident.
About 70% of Sri Lankans practise Buddhism
"The government must take decisive action to ensure that this sort of thing doesn't happen again," a party spokesman told AFP.
It also asked the Canadians to hold an internal inquiry.
One of the three monks who caused the security alert comes from Sri Lanka, while the other two are from Thailand.
Police said that Canadian diplomats panicked, seized them all and confiscated their passports and clothing for forensic tests.
Police say the monks were practically held prisoners within the mission and were denied the opportunity to inform friends and families of their plight.
The monks say they tried to explain to embassy staff that they used the talcum powder to prevent insects from damaging their passports.
A spokeswoman for the Canadian department of foreign affairs in Ottawa, Kimberly Phillips, told AFP that the Sri Lankan police reports were "completely erroneous".
She said that the monks were offered a private area within the high commission to take a shower and that new robes were provided for them so their contaminated garments could be scientifically examined.