The pair are among 30 people aboard the Greenpeace vessel Arctic Sunrise.
The ship was part of a protest against offshore drilling in the Arctic, with Greenpeace members attempting to scale a Russian-owned drilling platform.
The Russian Coast Guard seized the Arctic Sunrise and towed it toward shore.
It is now anchored near Murmansk.
Greenpeace spokesperson Christy Ferguson says the 30 people aboard come from 18 different countries.
She says diplomats from some of those countries, including Canada, were allowed on board the ship to offer assistance.
"Diplomats have been allowed to go onto the ship and meet with people from their country. And we do know that a Canadian diplomat was among those.
"So, Canadian diplomats have gone out to the ship and been able to meet. But we don't know anything more about the content of their conversation or any outcome."
The federal government has not commented on what services it is providing to the two Canadians.
Russian authorities say the Greenpeace activists could face piracy charges.
Ferguson calls that absurd.
"Piracy applies very specifically to cases where there is a violent assault for a commercial gain," she said. "These activists were acting peacefully."
Foreign Affairs Minister John Baird, asked Tuesday in Montreal about the incident, said he hasn't seen the charges against the Canadians, but he noted that Greenpeace in the past has taken "provocative actions" on the high seas.